From 9d02b43dee0d7fb18dfb13a00915550b1a3daa9f Mon Sep 17 00:00:00 2001 From: Olaf Hering Date: Thu, 1 Nov 2012 22:02:30 +0100 Subject: xen PVonHVM: use E820_Reserved area for shared_info This is a respin of 00e37bdb0113a98408de42db85be002f21dbffd3 ("xen PVonHVM: move shared_info to MMIO before kexec"). Currently kexec in a PVonHVM guest fails with a triple fault because the new kernel overwrites the shared info page. The exact failure depends on the size of the kernel image. This patch moves the pfn from RAM into an E820 reserved memory area. The pfn containing the shared_info is located somewhere in RAM. This will cause trouble if the current kernel is doing a kexec boot into a new kernel. The new kernel (and its startup code) can not know where the pfn is, so it can not reserve the page. The hypervisor will continue to update the pfn, and as a result memory corruption occours in the new kernel. The toolstack marks the memory area FC000000-FFFFFFFF as reserved in the E820 map. Within that range newer toolstacks (4.3+) will keep 1MB starting from FE700000 as reserved for guest use. Older Xen4 toolstacks will usually not allocate areas up to FE700000, so FE700000 is expected to work also with older toolstacks. In Xen3 there is no reserved area at a fixed location. If the guest is started on such old hosts the shared_info page will be placed in RAM. As a result kexec can not be used. Signed-off-by: Olaf Hering Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/xen/enlighten.c | 75 ++++++++++++++++++++++++++++++++++-------------- arch/x86/xen/suspend.c | 2 +- arch/x86/xen/xen-ops.h | 2 +- 3 files changed, 55 insertions(+), 24 deletions(-) (limited to 'arch/x86/xen') diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 586d83812b67..a90c3bb58bed 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1495,51 +1495,72 @@ asmlinkage void __init xen_start_kernel(void) #endif } -void __ref xen_hvm_init_shared_info(void) +#ifdef CONFIG_XEN_PVHVM +#define HVM_SHARED_INFO_ADDR 0xFE700000UL +static struct shared_info *xen_hvm_shared_info; +static unsigned long xen_hvm_sip_phys; +static int xen_major, xen_minor; + +static void xen_hvm_connect_shared_info(unsigned long pfn) { - int cpu; struct xen_add_to_physmap xatp; - static struct shared_info *shared_info_page = 0; - if (!shared_info_page) - shared_info_page = (struct shared_info *) - extend_brk(PAGE_SIZE, PAGE_SIZE); xatp.domid = DOMID_SELF; xatp.idx = 0; xatp.space = XENMAPSPACE_shared_info; - xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT; + xatp.gpfn = pfn; if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp)) BUG(); - HYPERVISOR_shared_info = (struct shared_info *)shared_info_page; +} +static void __init xen_hvm_set_shared_info(struct shared_info *sip) +{ + int cpu; + + HYPERVISOR_shared_info = sip; /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info * page, we use it in the event channel upcall and in some pvclock * related functions. We don't need the vcpu_info placement * optimizations because we don't use any pv_mmu or pv_irq op on - * HVM. - * When xen_hvm_init_shared_info is run at boot time only vcpu 0 is - * online but xen_hvm_init_shared_info is run at resume time too and - * in that case multiple vcpus might be online. */ - for_each_online_cpu(cpu) { + * HVM. */ + for_each_online_cpu(cpu) per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu]; +} + +/* Reconnect the shared_info pfn to a (new) mfn */ +void xen_hvm_resume_shared_info(void) +{ + xen_hvm_connect_shared_info(xen_hvm_sip_phys >> PAGE_SHIFT); +} + +/* Xen tools prior to Xen 4 do not provide a E820_Reserved area for guest usage. + * On these old tools the shared info page will be placed in E820_Ram. + * Xen 4 provides a E820_Reserved area at 0xFC000000, and this code expects + * that nothing is mapped up to HVM_SHARED_INFO_ADDR. + * Xen 4.3+ provides an explicit 1MB area at HVM_SHARED_INFO_ADDR which is used + * here for the shared info page. */ +static void __init xen_hvm_init_shared_info(void) +{ + if (xen_major < 4) { + xen_hvm_shared_info = extend_brk(PAGE_SIZE, PAGE_SIZE); + xen_hvm_sip_phys = __pa(xen_hvm_shared_info); + } else { + xen_hvm_sip_phys = HVM_SHARED_INFO_ADDR; + set_fixmap(FIX_PARAVIRT_BOOTMAP, xen_hvm_sip_phys); + xen_hvm_shared_info = + (struct shared_info *)fix_to_virt(FIX_PARAVIRT_BOOTMAP); } + xen_hvm_connect_shared_info(xen_hvm_sip_phys >> PAGE_SHIFT); + xen_hvm_set_shared_info(xen_hvm_shared_info); } -#ifdef CONFIG_XEN_PVHVM static void __init init_hvm_pv_info(void) { - int major, minor; uint32_t eax, ebx, ecx, edx, pages, msr, base; u64 pfn; base = xen_cpuid_base(); - cpuid(base + 1, &eax, &ebx, &ecx, &edx); - - major = eax >> 16; - minor = eax & 0xffff; - printk(KERN_INFO "Xen version %d.%d.\n", major, minor); - cpuid(base + 2, &pages, &msr, &ecx, &edx); pfn = __pa(hypercall_page); @@ -1590,12 +1611,22 @@ static void __init xen_hvm_guest_init(void) static bool __init xen_hvm_platform(void) { + uint32_t eax, ebx, ecx, edx, base; + if (xen_pv_domain()) return false; - if (!xen_cpuid_base()) + base = xen_cpuid_base(); + if (!base) return false; + cpuid(base + 1, &eax, &ebx, &ecx, &edx); + + xen_major = eax >> 16; + xen_minor = eax & 0xffff; + + printk(KERN_INFO "Xen version %d.%d.\n", xen_major, xen_minor); + return true; } diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c index 45329c8c226e..ae8a00c39de4 100644 --- a/arch/x86/xen/suspend.c +++ b/arch/x86/xen/suspend.c @@ -30,7 +30,7 @@ void xen_arch_hvm_post_suspend(int suspend_cancelled) { #ifdef CONFIG_XEN_PVHVM int cpu; - xen_hvm_init_shared_info(); + xen_hvm_resume_shared_info(); xen_callback_vector(); xen_unplug_emulated_devices(); if (xen_feature(XENFEAT_hvm_safe_pvclock)) { diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index a95b41744ad0..d2e73d19d366 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -40,7 +40,7 @@ void xen_enable_syscall(void); void xen_vcpu_restore(void); void xen_callback_vector(void); -void xen_hvm_init_shared_info(void); +void xen_hvm_resume_shared_info(void); void xen_unplug_emulated_devices(void); void __init xen_build_dynamic_phys_to_machine(void); -- cgit v1.2.3 From e3aa4e61b57da7574fdd1b4c9ca9bdee06a4d23e Mon Sep 17 00:00:00 2001 From: "Liu, Jinsong" Date: Thu, 8 Nov 2012 05:44:28 +0000 Subject: xen/acpi: revert pad config check in xen_check_mwait With Xen acpi pad logic added into kernel, we can now revert xen mwait related patch df88b2d96e36d9a9e325bfcd12eb45671cbbc937 ("xen/enlighten: Disable MWAIT_LEAF so that acpi-pad won't be loaded. "). The reason is, when running under newer Xen platform, Xen pad driver would be early loaded, so native pad driver would fail to be loaded, and hence no mwait/monitor #UD risk again. Another point is, only Xen4.2 or later support Xen acpi pad, so we won't expose mwait cpuid capability when running under older Xen platform. Signed-off-by: Liu, Jinsong Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/xen/enlighten.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'arch/x86/xen') diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index a90c3bb58bed..eb0edff5499b 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -287,8 +287,7 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx, static bool __init xen_check_mwait(void) { -#if defined(CONFIG_ACPI) && !defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR) && \ - !defined(CONFIG_ACPI_PROCESSOR_AGGREGATOR_MODULE) +#ifdef CONFIG_ACPI struct xen_platform_op op = { .cmd = XENPF_set_processor_pminfo, .u.set_pminfo.id = -1, @@ -309,6 +308,13 @@ static bool __init xen_check_mwait(void) if (!xen_initial_domain()) return false; + /* + * When running under platform earlier than Xen4.2, do not expose + * mwait, to avoid the risk of loading native acpi pad driver + */ + if (!xen_running_on_version_or_later(4, 2)) + return false; + ax = 1; cx = 0; -- cgit v1.2.3 From 394b40f62d7ae18a1c48c13fc483b8193f8c3a98 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Tue, 27 Nov 2012 11:39:40 -0500 Subject: xen/acpi: Move the xen_running_on_version_or_later function. As on ia64 builds we get: include/xen/interface/version.h: In function 'xen_running_on_version_or_later': include/xen/interface/version.h:76: error: implicit declaration of function 'HYPERVISOR_xen_version' We can later on make this function exportable if there are modules using part of it. For right now the only two users are built-in. Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/xen/enlighten.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'arch/x86/xen') diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index eb0edff5499b..3325cd9f7790 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -223,6 +223,21 @@ static void __init xen_banner(void) version >> 16, version & 0xffff, extra.extraversion, xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : ""); } +/* Check if running on Xen version (major, minor) or later */ +bool +xen_running_on_version_or_later(unsigned int major, unsigned int minor) +{ + unsigned int version; + + if (!xen_domain()) + return false; + + version = HYPERVISOR_xen_version(XENVER_version, NULL); + if ((((version >> 16) == major) && ((version & 0xffff) >= minor)) || + ((version >> 16) > major)) + return true; + return false; +} #define CPUID_THERM_POWER_LEAF 6 #define APERFMPERF_PRESENT 0 -- cgit v1.2.3 From 9a032e393a8bc888a9b0c898cbdb9db2cee7b536 Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Wed, 17 Oct 2012 13:37:49 -0700 Subject: xen: add pages parameter to xen_remap_domain_mfn_range Also introduce xen_unmap_domain_mfn_range. These are the parts of Mukesh's "xen/pvh: Implement MMU changes for PVH" which are also needed as a baseline for ARM privcmd support. The original patch was: Signed-off-by: Mukesh Rathor Signed-off-by: Konrad Rzeszutek Wilk This derivative is also: Signed-off-by: Ian Campbell --- arch/x86/xen/mmu.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'arch/x86/xen') diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 6226c99729b9..0f6386a5b437 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -2479,7 +2479,9 @@ static int remap_area_mfn_pte_fn(pte_t *ptep, pgtable_t token, int xen_remap_domain_mfn_range(struct vm_area_struct *vma, unsigned long addr, unsigned long mfn, int nr, - pgprot_t prot, unsigned domid) + pgprot_t prot, unsigned domid, + struct page **pages) + { struct remap_data rmd; struct mmu_update mmu_update[REMAP_BATCH_SIZE]; @@ -2523,3 +2525,14 @@ out: return err; } EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range); + +/* Returns: 0 success */ +int xen_unmap_domain_mfn_range(struct vm_area_struct *vma, + int numpgs, struct page **pages) +{ + if (!pages || !xen_feature(XENFEAT_auto_translated_physmap)) + return 0; + + return -EINVAL; +} +EXPORT_SYMBOL_GPL(xen_unmap_domain_mfn_range); -- cgit v1.2.3 From c2374bf57e7861039bb129ead538515502ef7860 Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Wed, 3 Oct 2012 12:17:50 +0100 Subject: xen: balloon: allow PVMMU interfaces to be compiled out The ARM platform has no concept of PVMMU and therefor no HYPERVISOR_update_va_mapping et al. Allow this code to be compiled out when not required. In some similar situations (e.g. P2M) we have defined dummy functions to avoid this, however I think we can/should draw the line at dummying out actual hypercalls. Signed-off-by: Ian Campbell Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/xen/Kconfig | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/x86/xen') diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig index fdce49c7aff6..c31ee77e1ec1 100644 --- a/arch/x86/xen/Kconfig +++ b/arch/x86/xen/Kconfig @@ -6,6 +6,7 @@ config XEN bool "Xen guest support" select PARAVIRT select PARAVIRT_CLOCK + select XEN_HAVE_PVMMU depends on X86_64 || (X86_32 && X86_PAE && !X86_VISWS) depends on X86_CMPXCHG && X86_TSC help -- cgit v1.2.3 From 7892f6928d0cd9ef9200a193183c2033b3143dab Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Tue, 16 Oct 2012 17:19:15 +0100 Subject: xen: correctly use xen_pfn_t in remap_domain_mfn_range. For Xen on ARM a PFN is 64 bits so we need to use the appropriate type here. Signed-off-by: Ian Campbell Acked-by: Stefano Stabellini Signed-off-by: Konrad Rzeszutek Wilk [v2: include the necessary header, Reported-by: Fengguang Wu ] --- arch/x86/xen/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/xen') diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 0f6386a5b437..fd8393f55069 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -2478,7 +2478,7 @@ static int remap_area_mfn_pte_fn(pte_t *ptep, pgtable_t token, int xen_remap_domain_mfn_range(struct vm_area_struct *vma, unsigned long addr, - unsigned long mfn, int nr, + xen_pfn_t mfn, int nr, pgprot_t prot, unsigned domid, struct page **pages) -- cgit v1.2.3 From a7be94ac8d69c037d08f0fd94b45a593f1d45176 Mon Sep 17 00:00:00 2001 From: Olaf Hering Date: Thu, 29 Nov 2012 15:32:26 +0100 Subject: xen/PVonHVM: fix compile warning in init_hvm_pv_info After merging the xen-two tree, today's linux-next build (x86_64 allmodconfig) produced this warning: arch/x86/xen/enlighten.c: In function 'init_hvm_pv_info': arch/x86/xen/enlighten.c:1617:16: warning: unused variable 'ebx' [-Wunused-variable] arch/x86/xen/enlighten.c:1617:11: warning: unused variable 'eax' [-Wunused-variable] Introduced by commit 9d02b43dee0d ("xen PVonHVM: use E820_Reserved area for shared_info"). Signed-off-by: Olaf Hering Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/xen/enlighten.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/xen') diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 3325cd9f7790..3aeaa933b527 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1578,7 +1578,7 @@ static void __init xen_hvm_init_shared_info(void) static void __init init_hvm_pv_info(void) { - uint32_t eax, ebx, ecx, edx, pages, msr, base; + uint32_t ecx, edx, pages, msr, base; u64 pfn; base = xen_cpuid_base(); -- cgit v1.2.3