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* x86/hyperv: Protect set_hv_tscchange_cb() against getting preemptedVitaly Kuznetsov2021-10-281-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following issue is observed with CONFIG_DEBUG_PREEMPT when KVM loads: KVM: vmx: using Hyper-V Enlightened VMCS BUG: using smp_processor_id() in preemptible [00000000] code: systemd-udevd/488 caller is set_hv_tscchange_cb+0x16/0x80 CPU: 1 PID: 488 Comm: systemd-udevd Not tainted 5.15.0-rc5+ #396 Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.0 12/17/2019 Call Trace: dump_stack_lvl+0x6a/0x9a check_preemption_disabled+0xde/0xe0 ? kvm_gen_update_masterclock+0xd0/0xd0 [kvm] set_hv_tscchange_cb+0x16/0x80 kvm_arch_init+0x23f/0x290 [kvm] kvm_init+0x30/0x310 [kvm] vmx_init+0xaf/0x134 [kvm_intel] ... set_hv_tscchange_cb() can get preempted in between acquiring smp_processor_id() and writing to HV_X64_MSR_REENLIGHTENMENT_CONTROL. This is not an issue by itself: HV_X64_MSR_REENLIGHTENMENT_CONTROL is a partition-wide MSR and it doesn't matter which particular CPU will be used to receive reenlightenment notifications. The only real problem can (in theory) be observed if the CPU whose id was acquired with smp_processor_id() goes offline before we manage to write to the MSR, the logic in hv_cpu_die() won't be able to reassign it correctly. Reported-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Link: https://lore.kernel.org/r/20211012155005.1613352-1-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* x86/hyperv: Remove duplicate includeJiapeng Chong2021-10-281-2/+0
| | | | | | | | | | | | Clean up the following includecheck warning: ./arch/x86/hyperv/ivm.c: linux/bitfield.h is included more than once. ./arch/x86/hyperv/ivm.c: linux/types.h is included more than once. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Link: https://lore.kernel.org/r/1635325022-99889-1-git-send-email-jiapeng.chong@linux.alibaba.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* x86/hyperv: Remove duplicated include in hv_initWan Jiabing2021-10-281-1/+0
| | | | | | | | | | | Fix following checkinclude.pl warning: ./arch/x86/hyperv/hv_init.c: linux/io.h is included more than once. The include is in line 13. Remove the duplicated here. Signed-off-by: Wan Jiabing <wanjiabing@vivo.com> Link: https://lore.kernel.org/r/20211026113249.30481-1-wanjiabing@vivo.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* x86/hyperv: Add ghcb hvcall support for SNP VMTianyu Lan2021-10-281-0/+75
| | | | | | | | | | | hyperv provides ghcb hvcall to handle VMBus HVCALL_SIGNAL_EVENT and HVCALL_POST_MESSAGE msg in SNP Isolation VM. Add such support. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20211025122116.264793-8-ltykernel@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* x86/hyperv: Add Write/Read MSR registers via ghcb pageTianyu Lan2021-10-282-29/+118
| | | | | | | | | | | | | | | | Hyperv provides GHCB protocol to write Synthetic Interrupt Controller MSR registers in Isolation VM with AMD SEV SNP and these registers are emulated by hypervisor directly. Hyperv requires to write SINTx MSR registers twice. First writes MSR via GHCB page to communicate with hypervisor and then writes wrmsr instruction to talk with paravisor which runs in VMPL0. Guest OS ID MSR also needs to be set via GHCB page. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20211025122116.264793-7-ltykernel@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* x86/hyperv: Add new hvcall guest address host visibility supportTianyu Lan2021-10-283-1/+112
| | | | | | | | | | | | | | | Add new hvcall guest address host visibility support to mark memory visible to host. Call it inside set_memory_decrypted /encrypted(). Add HYPERVISOR feature check in the hv_is_isolation_supported() to optimize in non-virtualization environment. Acked-by: Dave Hansen <dave.hansen@intel.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20211025122116.264793-4-ltykernel@gmail.com [ wei: fix conflicts with tip ] Signed-off-by: Wei Liu <wei.liu@kernel.org>
* x86/hyperv: Initialize GHCB page in Isolation VMTianyu Lan2021-10-281-7/+61
| | | | | | | | | | | | Hyperv exposes GHCB page via SEV ES GHCB MSR for SNP guest to communicate with hypervisor. Map GHCB page for all cpus to read/write MSR register and submit hvcall request via ghcb page. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20211025122116.264793-2-ltykernel@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* Merge tag 'hyperv-fixes-signed-20211007' of ↵Linus Torvalds2021-10-071-5/+15
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv fixes from Wei Liu: - Replace uuid.h with types.h in a header (Andy Shevchenko) - Avoid sleeping in atomic context in PCI driver (Long Li) - Avoid sending IPI to self when it shouldn't (Vitaly Kuznetsov) * tag 'hyperv-fixes-signed-20211007' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: Avoid erroneously sending IPI to 'self' hyper-v: Replace uuid.h with types.h PCI: hv: Fix sleep while in non-sleep context when removing child devices from the bus
| * x86/hyperv: Avoid erroneously sending IPI to 'self'Vitaly Kuznetsov2021-10-061-5/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __send_ipi_mask_ex() uses an optimization: when the target CPU mask is equal to 'cpu_present_mask' it uses 'HV_GENERIC_SET_ALL' format to avoid converting the specified cpumask to VP_SET. This case was overlooked when 'exclude_self' parameter was added. As the result, a spurious IPI to 'self' can be send. Reported-by: Thomas Gleixner <tglx@linutronix.de> Fixes: dfb5c1e12c28 ("x86/hyperv: remove on-stack cpumask from hv_send_ipi_mask_allbutself") Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20211006125016.941616-1-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* | Merge tag 'hyperv-fixes-signed-20210915' of ↵Linus Torvalds2021-09-151-17/+26
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv fixes from Wei Liu: - Fix kernel crash caused by uio driver (Vitaly Kuznetsov) - Remove on-stack cpumask from HV APIC code (Wei Liu) * tag 'hyperv-fixes-signed-20210915' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: remove on-stack cpumask from hv_send_ipi_mask_allbutself asm-generic/hyperv: provide cpumask_to_vpset_noself Drivers: hv: vmbus: Fix kernel crash upon unbinding a device from uio_hv_generic driver
| * x86/hyperv: remove on-stack cpumask from hv_send_ipi_mask_allbutselfWei Liu2021-09-111-17/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is not a good practice to allocate a cpumask on stack, given it may consume up to 1 kilobytes of stack space if the kernel is configured to have 8192 cpus. The internal helper functions __send_ipi_mask{,_ex} need to loop over the provided mask anyway, so it is not too difficult to skip `self' there. We can thus do away with the on-stack cpumask in hv_send_ipi_mask_allbutself. Adjust call sites of __send_ipi_mask as needed. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Suggested-by: Michael Kelley <mikelley@microsoft.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Fixes: 68bb7bfb7985d ("X86/Hyper-V: Enable IPI enlightenments") Signed-off-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210910185714.299411-3-wei.liu@kernel.org
* | x86/hyperv: fix root partition faults when writing to VP assist page MSRPraveen Kumar2021-08-041-20/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For root partition the VP assist pages are pre-determined by the hypervisor. The root kernel is not allowed to change them to different locations. And thus, we are getting below stack as in current implementation root is trying to perform write to specific MSR. [ 2.778197] unchecked MSR access error: WRMSR to 0x40000073 (tried to write 0x0000000145ac5001) at rIP: 0xffffffff810c1084 (native_write_msr+0x4/0x30) [ 2.784867] Call Trace: [ 2.791507] hv_cpu_init+0xf1/0x1c0 [ 2.798144] ? hyperv_report_panic+0xd0/0xd0 [ 2.804806] cpuhp_invoke_callback+0x11a/0x440 [ 2.811465] ? hv_resume+0x90/0x90 [ 2.818137] cpuhp_issue_call+0x126/0x130 [ 2.824782] __cpuhp_setup_state_cpuslocked+0x102/0x2b0 [ 2.831427] ? hyperv_report_panic+0xd0/0xd0 [ 2.838075] ? hyperv_report_panic+0xd0/0xd0 [ 2.844723] ? hv_resume+0x90/0x90 [ 2.851375] __cpuhp_setup_state+0x3d/0x90 [ 2.858030] hyperv_init+0x14e/0x410 [ 2.864689] ? enable_IR_x2apic+0x190/0x1a0 [ 2.871349] apic_intr_mode_init+0x8b/0x100 [ 2.878017] x86_late_time_init+0x20/0x30 [ 2.884675] start_kernel+0x459/0x4fb [ 2.891329] secondary_startup_64_no_verify+0xb0/0xbb Since the hypervisor already provides the VP assist pages for root partition, we need to memremap the memory from hypervisor for root kernel to use. The mapping is done in hv_cpu_init during bringup and is unmapped in hv_cpu_die during teardown. Signed-off-by: Praveen Kumar <kumarpraveen@linux.microsoft.com> Reviewed-by: Sunil Muthuswamy <sunilmut@microsoft.com> Link: https://lore.kernel.org/r/20210731120519.17154-1-kumarpraveen@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* | Drivers: hv: Move Hyper-V misc functionality to arch-neutral codeMichael Kelley2021-07-151-7/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | The check for whether hibernation is possible, and the enabling of Hyper-V panic notification during kexec, are both architecture neutral. Move the code from under arch/x86 and into drivers/hv/hv_common.c where it can also be used for ARM64. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1626287687-2045-4-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* | Drivers: hv: Add arch independent default functions for some Hyper-V handlersMichael Kelley2021-07-151-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Architecture independent Hyper-V code calls various arch-specific handlers when needed. To aid in supporting multiple architectures, provide weak defaults that can be overridden by arch-specific implementations where appropriate. But when arch-specific overrides aren't needed or haven't been implemented yet for a particular architecture, these stubs reduce the amount of clutter under arch/. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1626287687-2045-3-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* | Drivers: hv: Make portions of Hyper-V init code be arch neutralMichael Kelley2021-07-151-81/+10
|/ | | | | | | | | | | | | | | | | | The code to allocate and initialize the hv_vp_index array is architecture neutral. Similarly, the code to allocate and populate the hypercall input and output arg pages is architecture neutral. Move both sets of code out from arch/x86 and into utility functions in drivers/hv/hv_common.c that can be shared by Hyper-V initialization on ARM64. No functional changes. However, the allocation of the hypercall input and output arg pages is done differently so that the size is always the Hyper-V page size, even if not the same as the guest page size (such as with ARM64's 64K page size). Signed-off-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1626287687-2045-2-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* Drivers: hv: Move Hyper-V extended capability check to arch neutral codeMichael Kelley2021-06-051-47/+0
| | | | | | | | | | | | | | | | | | | | | The extended capability query code is currently under arch/x86, but it is architecture neutral, and is used by arch neutral code in the Hyper-V balloon driver. Hence the balloon driver fails to build on other architectures. Fix by moving the ext cap code out from arch/x86. Because it is also called from built-in architecture specific code, it can't be in a module, so the Makefile treats as built-in even when CONFIG_HYPERV is "m". Also drivers/Makefile is tweaked because this is the first occurrence of a Hyper-V file that is built-in even when CONFIG_HYPERV is "m". While here, update the hypercall status check to use the new helper function instead of open coding. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Sunil Muthuswamy <sunilmut@microsoft.com> Link: https://lore.kernel.org/r/1622669804-2016-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* Merge tag 'x86-mm-2021-04-29' of ↵Linus Torvalds2021-04-291-5/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 tlb updates from Ingo Molnar: "The x86 MM changes in this cycle were: - Implement concurrent TLB flushes, which overlaps the local TLB flush with the remote TLB flush. In testing this improved sysbench performance measurably by a couple of percentage points, especially if TLB-heavy security mitigations are active. - Further micro-optimizations to improve the performance of TLB flushes" * tag 'x86-mm-2021-04-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: smp: Micro-optimize smp_call_function_many_cond() smp: Inline on_each_cpu_cond() and on_each_cpu() x86/mm/tlb: Remove unnecessary uses of the inline keyword cpumask: Mark functions as pure x86/mm/tlb: Do not make is_lazy dirty for no reason x86/mm/tlb: Privatize cpu_tlbstate x86/mm/tlb: Flush remote and local TLBs concurrently x86/mm/tlb: Open-code on_each_cpu_cond_mask() for tlb_is_not_lazy() x86/mm/tlb: Unify flush_tlb_func_local() and flush_tlb_func_remote() smp: Run functions concurrently in smp_call_function_many_cond()
| * x86/mm/tlb: Flush remote and local TLBs concurrentlyNadav Amit2021-03-061-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To improve TLB shootdown performance, flush the remote and local TLBs concurrently. Introduce flush_tlb_multi() that does so. Introduce paravirtual versions of flush_tlb_multi() for KVM, Xen and hyper-v (Xen and hyper-v are only compile-tested). While the updated smp infrastructure is capable of running a function on a single local core, it is not optimized for this case. The multiple function calls and the indirect branch introduce some overhead, and might make local TLB flushes slower than they were before the recent changes. Before calling the SMP infrastructure, check if only a local TLB flush is needed to restore the lost performance in this common case. This requires to check mm_cpumask() one more time, but unless this mask is updated very frequently, this should impact performance negatively. Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> # Hyper-v parts Reviewed-by: Juergen Gross <jgross@suse.com> # Xen and paravirt parts Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lore.kernel.org/r/20210220231712.2475218-5-namit@vmware.com
* | Merge tag 'hyperv-next-signed-20210426' of ↵Linus Torvalds2021-04-267-89/+91
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull Hyper-V updates from Wei Liu: - VMBus enhancement - Free page reporting support for Hyper-V balloon driver - Some patches for running Linux as Arm64 Hyper-V guest - A few misc clean-up patches * tag 'hyperv-next-signed-20210426' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (30 commits) drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status x86/hyperv: Move hv_do_rep_hypercall to asm-generic video: hyperv_fb: Add ratelimit on error message Drivers: hv: vmbus: Increase wait time for VMbus unload Drivers: hv: vmbus: Initialize unload_event statically Drivers: hv: vmbus: Check for pending channel interrupts before taking a CPU offline Drivers: hv: vmbus: Drivers: hv: vmbus: Introduce CHANNELMSG_MODIFYCHANNEL_RESPONSE Drivers: hv: vmbus: Introduce and negotiate VMBus protocol version 5.3 Drivers: hv: vmbus: Use after free in __vmbus_open() Drivers: hv: vmbus: remove unused function Drivers: hv: vmbus: Remove unused linux/version.h header x86/hyperv: remove unused linux/version.h header x86/Hyper-V: Support for free page reporting x86/hyperv: Fix unused variable 'hi' warning in hv_apic_read x86/hyperv: Fix unused variable 'msr_val' warning in hv_qlock_wait hv: hyperv.h: a few mundane typo fixes drivers: hv: Fix EXPORT_SYMBOL and tab spaces issue Drivers: hv: vmbus: Drop error message when 'No request id available' asm-generic/hyperv: Add missing function prototypes per -W1 warnings clocksource/drivers/hyper-v: Move handling of STIMER0 interrupts ...
| * | drivers: hv: Create a consistent pattern for checking Hyper-V hypercall statusJoseph Salisbury2021-04-216-34/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is not a consistent pattern for checking Hyper-V hypercall status. Existing code uses a number of variants. The variants work, but a consistent pattern would improve the readability of the code, and be more conformant to what the Hyper-V TLFS says about hypercall status. Implemented new helper functions hv_result(), hv_result_success(), and hv_repcomp(). Changed the places where hv_do_hypercall() and related variants are used to use the helper functions. Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1618620183-9967-2-git-send-email-joseph.salisbury@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
| * | x86/hyperv: remove unused linux/version.h headerZheng Yongjun2021-04-021-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | That header is not needed in hv_proc.c. Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Yongjun Zheng <zhengyongjun3@huawei.com> Link: https://lore.kernel.org/r/20210326064942.3263776-1-zhengyongjun3@huawei.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
| * | x86/Hyper-V: Support for free page reportingSunil Muthuswamy2021-03-241-1/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linux has support for free page reporting now (36e66c554b5c) for virtualized environment. On Hyper-V when virtually backed VMs are configured, Hyper-V will advertise cold memory discard capability, when supported. This patch adds the support to hook into the free page reporting infrastructure and leverage the Hyper-V cold memory discard hint hypercall to report/free these pages back to the host. Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com> Tested-by: Matheus Castello <matheus@castello.eng.br> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/SN4PR2101MB0880121FA4E2FEC67F35C1DCC0649@SN4PR2101MB0880.namprd21.prod.outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
| * | x86/hyperv: Fix unused variable 'hi' warning in hv_apic_readXu Yihang2021-03-241-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fixes the following W=1 kernel build warning(s): arch/x86/hyperv/hv_apic.c:58:15: warning: variable ‘hi’ set but not used [-Wunused-but-set-variable] Compiled with CONFIG_HYPERV enabled: make allmodconfig ARCH=x86_64 CROSS_COMPILE=x86_64-linux-gnu- make W=1 arch/x86/hyperv/hv_apic.o ARCH=x86_64 CROSS_COMPILE=x86_64-linux-gnu- HV_X64_MSR_EOI occupies bit 31:0 and HV_X64_MSR_TPR occupies bit 7:0, which means the higher 32 bits are not really used. Cast the variable hi to void to silence this warning. Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Xu Yihang <xuyihang@huawei.com> Link: https://lore.kernel.org/r/20210323025013.191533-1-xuyihang@huawei.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
| * | x86/hyperv: Fix unused variable 'msr_val' warning in hv_qlock_waitXu Yihang2021-03-241-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fixes the following W=1 kernel build warning(s): arch/x86/hyperv/hv_spinlock.c:28:16: warning: variable ‘msr_val’ set but not used [-Wunused-but-set-variable] unsigned long msr_val; As Hypervisor Top-Level Functional Specification states in chapter 7.5 Virtual Processor Idle Sleep State, "A partition which possesses the AccessGuestIdleMsr privilege (refer to section 4.2.2) may trigger entry into the virtual processor idle sleep state through a read to the hypervisor-defined MSR HV_X64_MSR_GUEST_IDLE". That means only a read of the MSR is necessary. The returned value msr_val is not used. Cast it to void to silence this warning. Reference: https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Xu Yihang <xuyihang@huawei.com> Link: https://lore.kernel.org/r/20210323024302.174434-1-xuyihang@huawei.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
| * | clocksource/drivers/hyper-v: Move handling of STIMER0 interruptsMichael Kelley2021-03-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | STIMER0 interrupts are most naturally modeled as per-cpu IRQs. But because x86/x64 doesn't have per-cpu IRQs, the core STIMER0 interrupt handling machinery is done in code under arch/x86 and Linux IRQs are not used. Adding support for ARM64 means adding equivalent code using per-cpu IRQs under arch/arm64. A better model is to treat per-cpu IRQs as the normal path (which it is for modern architectures), and the x86/x64 path as the exception. Do this by incorporating standard Linux per-cpu IRQ allocation into the main SITMER0 driver code, and bypass it in the x86/x64 exception case. For x86/x64, special case code is retained under arch/x86, but no STIMER0 interrupt handling code is needed under arch/arm64. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/1614721102-2241-11-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
| * | Drivers: hv: vmbus: Move hyperv_report_panic_msg to arch neutral codeMichael Kelley2021-03-081-27/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the new Hyper-V MSR set function, hyperv_report_panic_msg() can be architecture neutral, so move it out from under arch/x86 and merge into hv_kmsg_dump(). This move also avoids needing a separate implementation under arch/arm64. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/1614721102-2241-5-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
| * | Drivers: hv: Redo Hyper-V synthetic MSR get/set functionsMichael Kelley2021-03-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current code defines a separate get and set macro for each Hyper-V synthetic MSR used by the VMbus driver. Furthermore, the get macro can't be converted to a standard function because the second argument is modified in place, which is somewhat bad form. Redo this by providing a single get and a single set function that take a parameter specifying the MSR to be operated on. Fixup usage of the get function. Calling locations are no more complex than before, but the code under arch/x86 and the upcoming code under arch/arm64 is significantly simplified. Also standardize the names of Hyper-V synthetic MSRs that are architecture neutral. But keep the old x86-specific names as aliases that can be removed later when all references (particularly in KVM code) have been cleaned up in a separate patch series. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/1614721102-2241-4-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
| * | Drivers: hv: vmbus: Move Hyper-V page allocator to arch neutral codeMichael Kelley2021-03-081-22/+0
| |/ | | | | | | | | | | | | | | | | | | | | | | | | The Hyper-V page allocator functions are implemented in an architecture neutral way. Move them into the architecture neutral VMbus module so a separate implementation for ARM64 is not needed. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/1614721102-2241-2-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* / x86: Fix various typos in commentsIngo Molnar2021-03-181-2/+2
|/ | | | | | | | | | | | | | Fix ~144 single-word typos in arch/x86/ code comments. Doing this in a single commit should reduce the churn. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: linux-kernel@vger.kernel.org
* iommu/hyperv: setup an IO-APIC IRQ remapping domain for root partitionWei Liu2021-02-111-0/+25
| | | | | | | | | | | Just like MSI/MSI-X, IO-APIC interrupts are remapped by Microsoft Hypervisor when Linux runs as the root partition. Implement an IRQ domain to handle mapping and unmapping of IO-APIC interrupts. Signed-off-by: Wei Liu <wei.liu@kernel.org> Acked-by: Joerg Roedel <joro@8bytes.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210203150435.27941-17-wei.liu@kernel.org
* x86/hyperv: implement an MSI domain for root partitionWei Liu2021-02-113-1/+370
| | | | | | | | | | | | | | | When Linux runs as the root partition on Microsoft Hypervisor, its interrupts are remapped. Linux will need to explicitly map and unmap interrupts for hardware. Implement an MSI domain to issue the correct hypercalls. And initialize this irq domain as the default MSI irq domain. Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com> Co-Developed-by: Sunil Muthuswamy <sunilmut@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210203150435.27941-16-wei.liu@kernel.org
* x86/hyperv: provide a bunch of helper functionsWei Liu2021-02-112-1/+220
| | | | | | | | | | | | | | | They are used to deposit pages into Microsoft Hypervisor and bring up logical and virtual processors. Signed-off-by: Lillian Grassin-Drake <ligrassi@microsoft.com> Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Co-Developed-by: Lillian Grassin-Drake <ligrassi@microsoft.com> Co-Developed-by: Sunil Muthuswamy <sunilmut@microsoft.com> Co-Developed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210203150435.27941-10-wei.liu@kernel.org
* x86/hyperv: handling hypercall page setup for rootWei Liu2021-02-111-3/+34
| | | | | | | | | | | | | | | | | | | When Linux is running as the root partition, the hypercall page will have already been setup by Hyper-V. Copy the content over to the allocated page. Add checks to hv_suspend & co to bail early because they are not supported in this setup yet. Signed-off-by: Lillian Grassin-Drake <ligrassi@microsoft.com> Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Co-Developed-by: Lillian Grassin-Drake <ligrassi@microsoft.com> Co-Developed-by: Sunil Muthuswamy <sunilmut@microsoft.com> Co-Developed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210203150435.27941-8-wei.liu@kernel.org
* x86/hyperv: extract partition ID from Microsoft Hypervisor if necessaryWei Liu2021-02-111-0/+26
| | | | | | | | | | We will need the partition ID for executing some hypercalls later. Signed-off-by: Lillian Grassin-Drake <ligrassi@microsoft.com> Co-Developed-by: Sunil Muthuswamy <sunilmut@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210203150435.27941-7-wei.liu@kernel.org
* x86/hyperv: allocate output arg pages if requiredWei Liu2021-02-111-5/+30
| | | | | | | | | | | | | | When Linux runs as the root partition, it will need to make hypercalls which return data from the hypervisor. Allocate pages for storing results when Linux runs as the root partition. Signed-off-by: Lillian Grassin-Drake <ligrassi@microsoft.com> Co-Developed-by: Lillian Grassin-Drake <ligrassi@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210203150435.27941-6-wei.liu@kernel.org
* x86/hyperv: Load/save the Isolation Configuration leafAndrea Parri (Microsoft)2021-02-111-0/+15
| | | | | | | | | | | | | | | | | | | | If bit 22 of Group B Features is set, the guest has access to the Isolation Configuration CPUID leaf. On x86, the first four bits of EAX in this leaf provide the isolation type of the partition; we entail three isolation types: 'SNP' (hardware-based isolation), 'VBS' (software-based isolation), and 'NONE' (no isolation). Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: x86@kernel.org Cc: linux-arch@vger.kernel.org Link: https://lore.kernel.org/r/20210201144814.2701-2-parri.andrea@gmail.com Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
* x86/hyperv: Initialize clockevents after LAPIC is initializedDexuan Cui2021-01-171-3/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With commit 4df4cb9e99f8, the Hyper-V direct-mode STIMER is actually initialized before LAPIC is initialized: see apic_intr_mode_init() x86_platform.apic_post_init() hyperv_init() hv_stimer_alloc() apic_bsp_setup() setup_local_APIC() setup_local_APIC() temporarily disables LAPIC, initializes it and re-eanble it. The direct-mode STIMER depends on LAPIC, and when it's registered, it can be programmed immediately and the timer can fire very soon: hv_stimer_init clockevents_config_and_register clockevents_register_device tick_check_new_device tick_setup_device tick_setup_periodic(), tick_setup_oneshot() clockevents_program_event When the timer fires in the hypervisor, if the LAPIC is in the disabled state, new versions of Hyper-V ignore the event and don't inject the timer interrupt into the VM, and hence the VM hangs when it boots. Note: when the VM starts/reboots, the LAPIC is pre-enabled by the firmware, so the window of LAPIC being temporarily disabled is pretty small, and the issue can only happen once out of 100~200 reboots for a 40-vCPU VM on one dev host, and on another host the issue doesn't reproduce after 2000 reboots. The issue is more noticeable for kdump/kexec, because the LAPIC is disabled by the first kernel, and stays disabled until the kdump/kexec kernel enables it. This is especially an issue to a Generation-2 VM (for which Hyper-V doesn't emulate the PIT timer) when CONFIG_HZ=1000 (rather than CONFIG_HZ=250) is used. Fix the issue by moving hv_stimer_alloc() to a later place where the LAPIC timer is initialized. Fixes: 4df4cb9e99f8 ("x86/hyperv: Initialize clockevents earlier in CPU onlining") Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210116223136.13892-1-decui@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* x86/hyperv: check cpu mask after interrupt has been disabledWei Liu2021-01-061-3/+9
| | | | | | | | | | | | | | | | We've observed crashes due to an empty cpu mask in hyperv_flush_tlb_others. Obviously the cpu mask in question is changed between the cpumask_empty call at the beginning of the function and when it is actually used later. One theory is that an interrupt comes in between and a code path ends up changing the mask. Move the check after interrupt has been disabled to see if it fixes the issue. Signed-off-by: Wei Liu <wei.liu@kernel.org> Cc: stable@kernel.org Link: https://lore.kernel.org/r/20210105175043.28325-1-wei.liu@kernel.org Reviewed-by: Michael Kelley <mikelley@microsoft.com>
* x86/hyperv: Fix kexec panic/hang issuesDexuan Cui2021-01-051-0/+4
| | | | | | | | | | | | | | | | | | | | | Currently the kexec kernel can panic or hang due to 2 causes: 1) hv_cpu_die() is not called upon kexec, so the hypervisor corrupts the old VP Assist Pages when the kexec kernel runs. The same issue is fixed for hibernation in commit 421f090c819d ("x86/hyperv: Suspend/resume the VP assist page for hibernation"). Now fix it for kexec. 2) hyperv_cleanup() is called too early. In the kexec path, the other CPUs are stopped in hv_machine_shutdown() -> native_machine_shutdown(), so between hv_kexec_handler() and native_machine_shutdown(), the other CPUs can still try to access the hypercall page and cause panic. The workaround "hv_hypercall_pg = NULL;" in hyperv_cleanup() is unreliabe. Move hyperv_cleanup() to a better place. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201222065541.24312-1-decui@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* Merge tag 'hyperv-fixes-signed' of ↵Linus Torvalds2020-11-051-5/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv fixes from Wei Liu: - clarify a comment (Michael Kelley) - change a pr_warn() to pr_info() (Olaf Hering) * tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: Clarify comment on x2apic mode hv_balloon: disable warning when floor reached
| * x86/hyperv: Clarify comment on x2apic modeMichael Kelley2020-10-261-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | The comment about Hyper-V accessors is unclear regarding their potential use in x2apic mode, as is the associated commit message in e211288b72f1. Clarify that while the architectural and synthetic MSRs are equivalent in x2apic mode, the full set of xapic accessors cannot be used because of register layout differences. Fixes: e211288b72f1 ("x86/hyperv: Make vapic support x2apic mode") Signed-off-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1603723972-81303-1-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* | x86/hyperv: Remove aliases with X64 in their nameJoseph Salisbury2020-09-272-5/+5
|/ | | | | | | | | | | | | | | | | In the architecture independent version of hyperv-tlfs.h, commit c55a844f46f958b removed the "X64" in the symbol names so they would make sense for both x86 and ARM64. That commit added aliases with the "X64" in the x86 version of hyperv-tlfs.h so that existing x86 code would continue to compile. As a cleanup, update the x86 code to use the symbols without the "X64", then remove the aliases. There's no functional change. Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Link: https://lore.kernel.org/r/1601130386-11111-1-git-send-email-jsalisbury@linux.microsoft.com
* vmalloc: fix the owner argument for the new __vmalloc_node_range callersChristoph Hellwig2020-07-031-1/+2
| | | | | | | | | | | | | | Fix the recently added new __vmalloc_node_range callers to pass the correct values as the owner for display in /proc/vmallocinfo. Fixes: 800e26b81311 ("x86/hyperv: allocate the hypercall page with only read and execute bits") Fixes: 10d5e97c1bf8 ("arm64: use PAGE_KERNEL_ROX directly in alloc_insn_page") Fixes: 7a0e27b2a0ce ("mm: remove vmalloc_exec") Reported-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200627075649.2455097-1-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86/hyperv: allocate the hypercall page with only read and execute bitsChristoph Hellwig2020-06-261-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "fix a hyperv W^X violation and remove vmalloc_exec" Dexuan reported a W^X violation due to the fact that the hyper hypercall page due switching it to be allocated using vmalloc_exec. The problem is that PAGE_KERNEL_EXEC as used by vmalloc_exec actually sets writable permissions in the pte. This series fixes the issue by switching to the low-level __vmalloc_node_range interface that allows specifing more detailed permissions instead. It then also open codes the other two callers and removes the somewhat confusing vmalloc_exec interface. Peter noted that the hyper hypercall page allocation also has another long standing issue in that it shouldn't use the full vmalloc but just the module space. This issue is so far theoretical as the allocation is done early in the boot process. I plan to fix it with another bigger series for 5.9. This patch (of 3): Avoid a W^X violation cause by the fact that PAGE_KERNEL_EXEC includes the writable bit. For this resurrect the removed PAGE_KERNEL_RX definition, but as PAGE_KERNEL_ROX to match arm64 and powerpc. Link: http://lkml.kernel.org/r/20200618064307.32739-2-hch@lst.de Fixes: 78bb17f76edc ("x86/hyperv: use vmalloc_exec for the hypercall page") Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Dexuan Cui <decui@microsoft.com> Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com> Acked-by: Wei Liu <wei.liu@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Jessica Yu <jeyu@kernel.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86/entry: Convert various hypervisor vectors to IDTENTRY_SYSVECThomas Gleixner2020-06-111-6/+3
| | | | | | | | | | | | | | | | | | | | Convert various hypervisor vectors to IDTENTRY_SYSVEC: - Implement the C entry point with DEFINE_IDTENTRY_SYSVEC - Emit the ASM stub with DECLARE_IDTENTRY_SYSVEC - Remove the ASM idtentries in 64-bit - Remove the BUILD_INTERRUPT entries in 32-bit - Remove the old prototypes No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20200521202119.647997594@linutronix.de
* mm: remove the pgprot argument to __vmallocChristoph Hellwig2020-06-021-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The pgprot argument to __vmalloc is always PAGE_KERNEL now, so remove it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> [hyperv] Acked-by: Gao Xiang <xiang@kernel.org> [erofs] Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Wei Liu <wei.liu@kernel.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Airlie <airlied@linux.ie> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Link: http://lkml.kernel.org/r/20200414131348.444715-22-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86/hyperv: use vmalloc_exec for the hypercall pageChristoph Hellwig2020-06-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "decruft the vmalloc API", v2. Peter noticed that with some dumb luck you can toast the kernel address space with exported vmalloc symbols. I used this as an opportunity to decruft the vmalloc.c API and make it much more systematic. This also removes any chance to create vmalloc mappings outside the designated areas or using executable permissions from modules. Besides that it removes more than 300 lines of code. This patch (of 29): Use the designated helper for allocating executable kernel memory, and remove the now unused PAGE_KERNEL_RX define. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Acked-by: Wei Liu <wei.liu@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Airlie <airlied@linux.ie> Cc: Gao Xiang <xiang@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Link: http://lkml.kernel.org/r/20200414131348.444715-1-hch@lst.de Link: http://lkml.kernel.org/r/20200414131348.444715-2-hch@lst.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86/hyperv: Properly suspend/resume reenlightenment notificationsVitaly Kuznetsov2020-05-131-2/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Errors during hibernation with reenlightenment notifications enabled were reported: [ 51.730435] PM: hibernation entry [ 51.737435] PM: Syncing filesystems ... ... [ 54.102216] Disabling non-boot CPUs ... [ 54.106633] smpboot: CPU 1 is now offline [ 54.110006] unchecked MSR access error: WRMSR to 0x40000106 (tried to write 0x47c72780000100ee) at rIP: 0xffffffff90062f24 native_write_msr+0x4/0x20) [ 54.110006] Call Trace: [ 54.110006] hv_cpu_die+0xd9/0xf0 ... Normally, hv_cpu_die() just reassigns reenlightenment notifications to some other CPU when the CPU receiving them goes offline. Upon hibernation, there is no other CPU which is still online so cpumask_any_but(cpu_online_mask) returns >= nr_cpu_ids and using it as hv_vp_index index is incorrect. Disable the feature when cpumask_any_but() fails. Also, as we now disable reenlightenment notifications upon hibernation we need to restore them on resume. Check if hv_reenlightenment_cb was previously set and restore from hv_resume(). Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20200512160153.134467-1-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* x86/hyperv: Suspend/resume the VP assist page for hibernationDexuan Cui2020-04-211-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unlike the other CPUs, CPU0 is never offlined during hibernation, so in the resume path, the "new" kernel's VP assist page is not suspended (i.e. not disabled), and later when we jump to the "old" kernel, the page is not properly re-enabled for CPU0 with the allocated page from the old kernel. So far, the VP assist page is used by hv_apic_eoi_write(), and is also used in the case of nested virtualization (running KVM atop Hyper-V). For hv_apic_eoi_write(), when the page is not properly re-enabled, hvp->apic_assist is always 0, so the HV_X64_MSR_EOI MSR is always written. This is not ideal with respect to performance, but Hyper-V can still correctly handle this according to the Hyper-V spec; nevertheless, Linux still must update the Hyper-V hypervisor with the correct VP assist page to prevent Hyper-V from writing to the stale page, which causes guest memory corruption and consequently may have caused the hangs and triple faults seen during non-boot CPUs resume. Fix the issue by calling hv_cpu_die()/hv_cpu_init() in the syscore ops. Without the fix, hibernation can fail at a rate of 1/300 ~ 1/500. With the fix, hibernation can pass a long-haul test of 2000 runs. In the case of nested virtualization, disabling/reenabling the assist page upon hibernation may be unsafe if there are active L2 guests. It looks KVM should be enhanced to abort the hibernation request if there is any active L2 guest. Fixes: 05bd330a7fd8 ("x86/hyperv: Suspend/resume the hypercall page for hibernation") Cc: stable@vger.kernel.org Signed-off-by: Dexuan Cui <decui@microsoft.com> Link: https://lore.kernel.org/r/1587437171-2472-1-git-send-email-decui@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
* x86/Hyper-V: Report crash data in die() when panic_on_oops is setTianyu Lan2020-04-111-1/+5
| | | | | | | | | | | | | | | When oops happens with panic_on_oops unset, the oops thread is killed by die() and system continues to run. In such case, guest should not report crash register data to host since system still runs. Check panic_on_oops and return directly in hyperv_report_panic() when the function is called in the die() and panic_on_oops is unset. Fix it. Fixes: 7ed4325a44ea ("Drivers: hv: vmbus: Make panic reporting to be more useful") Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200406155331.2105-7-Tianyu.Lan@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-20 14:21:08 +0000