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* KVM: VMX: Only reload guest msrs if they are already loadedAvi Kivity2007-07-161-1/+2
| | | | | | | | | | If we set an msr via an ioctl() instead of by handling a guest exit, we have the host state loaded, so reloading the msrs would clobber host state instead of guest state. This fixes a host oops (and loss of a cpu) on a guest reboot. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Consolidate guest fpu activation and deactivationAvi Kivity2007-07-161-19/+31
| | | | | | Easier to keep track of where the fpu is this way. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Rationalize exception bitmap usageAvi Kivity2007-07-161-21/+21
| | | | | | | | Everyone owns a piece of the exception bitmap, but they happily write to the entire thing like there's no tomorrow. Centralize handling in update_exception_bitmap() and have everyone call that. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Move some more msr mangling into vmx_save_host_state()Avi Kivity2007-07-161-7/+7
| | | | Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Fix potential guest state leak into hostAvi Kivity2007-07-161-71/+89
| | | | | | | | | | | The lightweight vmexit path avoids saving and reloading certain host state. However in certain cases lightweight vmexit handling can schedule() which requires reloading the host state. So we store the host state in the vcpu structure, and reloaded it if we relinquish the vcpu. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Be more careful restoring fs on lightweight vmexitAvi Kivity2007-07-161-11/+11
| | | | | | | | i386 wants fs for accessing the pda even on a lightweight exit, so ensure we can always restore it. This fixes a regression on i386 introduced by the lightweight vmexit patch. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Unindent some codeAvi Kivity2007-07-161-29/+29
| | | | Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Avoid saving and restoring some host CPU state on lightweight vmexitAvi Kivity2007-07-161-45/+60
| | | | | | | | | | | | Many msrs and the like will only be used by the host if we schedule() or return to userspace. Therefore, we avoid saving them if we handle the exit within the kernel, and if a reschedule is not requested. Based on a patch from Eddie Dong <eddie.dong@intel.com> with a couple of fixes by me. Signed-off-by: Yaozu(Eddie) Dong <eddie.dong@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: VMX: Enable io bitmaps to avoid IO port 0x80 VMEXITsHe, Qing2007-07-161-4/+46
| | | | | | | | | | | | | This patch enables IO bitmaps control on vmx and unmask the 0x80 port to avoid VMEXITs caused by accessing port 0x80. 0x80 is used as delays (see include/asm/io.h), and handling VMEXITs on its access is unnecessary but slows things down. This patch improves kernel build test at around 3%~5%. Because every VM uses the same io bitmap, it is shared between all VMs rather than a per-VM data structure. Signed-off-by: Qing He <qing.he@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Prevent guest fpu state from leaking into the hostAvi Kivity2007-06-151-9/+3
| | | | | | | | | The lazy fpu changes did not take into account that some vmexit handlers can sleep. Move loading the guest state into the inner loop so that it can be reloaded if necessary, and move loading the host state into vmx_vcpu_put() so it can be performed whenever we relinquish the vcpu. Signed-off-by: Avi Kivity <avi@qumranet.com>
* kvm: fix section mismatch warning in kvm-intel.oSam Ravnborg2007-06-011-1/+1
| | | | | | | | | | | | | | | | | | Fix following section mismatch warning in kvm-intel.o: WARNING: o-i386/drivers/kvm/kvm-intel.o(.init.text+0xbd): Section mismatch: reference to .exit.text: (between 'hardware_setup' and 'vmx_disabled_by_bios') The function free_kvm_area is used in the function alloc_kvm_area which is marked __init. The __exit area is discarded by some archs during link-time if a module is built-in resulting in an oops. Note: This warning is only seen by my local copy of modpost but the change will soon hit upstream. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Detach sched.h from mm.hAlexey Dobriyan2007-05-211-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | First thing mm.h does is including sched.h solely for can_do_mlock() inline function which has "current" dereference inside. By dealing with can_do_mlock() mm.h can be detached from sched.h which is good. See below, why. This patch a) removes unconditional inclusion of sched.h from mm.h b) makes can_do_mlock() normal function in mm/mlock.c c) exports can_do_mlock() to not break compilation d) adds sched.h inclusions back to files that were getting it indirectly. e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were getting them indirectly Net result is: a) mm.h users would get less code to open, read, preprocess, parse, ... if they don't need sched.h b) sched.h stops being dependency for significant number of files: on x86_64 allmodconfig touching sched.h results in recompile of 4083 files, after patch it's only 3744 (-8.3%). Cross-compile tested on all arm defconfigs, all mips defconfigs, all powerpc defconfigs, alpha alpha-up arm i386 i386-up i386-defconfig i386-allnoconfig ia64 ia64-up m68k mips parisc parisc-up powerpc powerpc-up s390 s390-up sparc sparc-up sparc64 sparc64-up um-x86_64 x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig as well as my two usual configs. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* KVM: Remove unused 'instruction_length'Avi Kivity2007-05-031-1/+0
| | | | | | | As we no longer emulate in userspace, this is meaningless. We don't compute it on SVM anyway. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: VMX: Add lazy FPU support for VTAnthony Liguori2007-05-031-5/+56
| | | | | | | | Only save/restore the FPU host state when the guest is actually using the FPU. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: VMX: Properly shadow the CR0 register in the vcpu structAnthony Liguori2007-05-031-6/+8
| | | | | | | | Set all of the host mask bits for CR0 so that we can maintain a proper shadow of CR0. This exposes CR0.TS, paving the way for lazy fpu handling. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Don't complain about cpu erratum AA15Avi Kivity2007-05-031-2/+0
| | | | | | It slows down Windows x64 horribly. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Per-vcpu statisticsAvi Kivity2007-05-031-9/+9
| | | | | | | | Make the exit statistics per-vcpu instead of global. This gives a 3.5% boost when running one virtual machine per core on my two socket dual core (4 cores total) machine. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: VMX: Only save/restore MSR_K6_STAR if necessaryAvi Kivity2007-05-031-0/+16
| | | | | | | | | | Intel hosts only support syscall/sysret in long more (and only if efer.sce is enabled), so only reload the related MSR_K6_STAR if the guest will actually be able to use it. This reduces vmexit cost by about 500 cycles (6400 -> 5870) on my setup. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Fold drivers/kvm/kvm_vmx.h into drivers/kvm/vmx.cAvi Kivity2007-05-031-1/+6
| | | | | | No meat in that file. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: VMX: Don't switch 64-bit msrs for 32-bit guestsAvi Kivity2007-05-031-16/+42
| | | | | | | | | Some msrs are only used by x86_64 instructions, and are therefore not needed when the guest is legacy mode. By not bothering to switch them, we reduce vmexit latency by 2400 cycles (from about 8800) when running a 32-bt guest on a 64-bit host. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: VMX: Reduce unnecessary saving of host msrsAvi Kivity2007-05-031-1/+11
| | | | | | | | | | | THe automatically switched msrs are never changed on the host (with the exception of MSR_KERNEL_GS_BASE) and thus there is no need to save them on every vm entry. This reduces vmexit latency by ~400 cycles on i386 and by ~900 cycles (10%) on x86_64. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Fix overflow bug in overflow detection codeEric Sesterhenn / Snakebyte2007-05-031-1/+1
| | | | | | | | | | | | | The expression sp - 6 < sp where sp is a u16 is undefined in C since 'sp - 6' is promoted to int, and signed overflow is undefined in C. gcc 4.2 actually warns about it. Replace with a simpler test. Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Simply gfn_to_page()Avi Kivity2007-05-031-3/+3
| | | | | | | | | | | | Mapping a guest page to a host page is a common operation. Currently, one has first to find the memory slot where the page belongs (gfn_to_memslot), then locate the page itself (gfn_to_page()). This is clumsy, and also won't work well with memory aliases. So simplify gfn_to_page() not to require memory slot translation first, and instead do it internally. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Remove debug messageAvi Kivity2007-05-031-1/+0
| | | | | | No longer interesting. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Hack real-mode segments on vmx from KVM_SET_SREGSAvi Kivity2007-05-031-1/+8
| | | | | | | | | | As usual, we need to mangle segment registers when emulating real mode as vm86 has specific constraints. We special case the reset segment base, and set the "access rights" (or descriptor flags) to vm86 comaptible values. This fixes reboot on vmx. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Remove set_cr0_no_modeswitch() arch opAvi Kivity2007-05-031-17/+0
| | | | | | | | | set_cr0_no_modeswitch() was a hack to avoid corrupting segment registers. As we now cache the protected mode values on entry to real mode, this isn't an issue anymore, and it interferes with reboot (which usually _is_ a modeswitch). Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Workaround vmx inability to virtualize the reset stateAvi Kivity2007-05-031-0/+2
| | | | | | | | | | | | | | The reset state has cs.selector == 0xf000 and cs.base == 0xffff0000, which aren't compatible with vm86 mode, which is used for real mode virtualization. When we create a vcpu, we set cs.base to 0xf0000, but if we get there by way of a reset, the values are inconsistent and vmx refuses to enter guest mode. Workaround by detecting the state and munging it appropriately. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Avoid guest virtual addresses in string pio userspace interfaceAvi Kivity2007-05-031-20/+20
| | | | | | | | | | | | | | | The current string pio interface communicates using guest virtual addresses, relying on userspace to translate addresses and to check permissions. This interface cannot fully support guest smp, as the check needs to take into account two pages at one in case an unaligned string transfer straddles a page boundary. Change the interface not to communicate guest addresses at all; instead use a buffer page (mmaped by userspace) and do transfers there. The kernel manages the virtual to physical translation and can perform the checks atomically by taking the appropriate locks. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Add a special exit reason when exiting due to an interruptAvi Kivity2007-05-031-0/+2
| | | | | | | | This is redundant, as we also return -EINTR from the ioctl, but it allows us to examine the exit_reason field on resume without seeing old data. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Fold kvm_run::exit_type into kvm_run::exit_reasonAvi Kivity2007-05-031-4/+3
| | | | | | | | | Currently, userspace is told about the nature of the last exit from the guest using two fields, exit_type and exit_reason, where exit_type has just two enumerations (and no need for more). So fold exit_type into exit_reason, reducing the complexity of determining what really happened. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Handle cpuid in the kernel instead of punting to userspaceAvi Kivity2007-05-031-2/+2
| | | | | | | | | | | | | | KVM used to handle cpuid by letting userspace decide what values to return to the guest. We now handle cpuid completely in the kernel. We still let userspace decide which values the guest will see by having userspace set up the value table beforehand (this is necessary to allow management software to set the cpu features to the least common denominator, so that live migration can work). The motivation for the change is that kvm kernel code can be impacted by cpuid features, for example the x86 emulator. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Do not communicate to userspace through cpu registers during PIOAvi Kivity2007-05-031-0/+2
| | | | | | | | | | | | | Currently when passing the a PIO emulation request to userspace, we rely on userspace updating %rax (on 'in' instructions) and %rsi/%rdi/%rcx (on string instructions). This (a) requires two extra ioctls for getting and setting the registers and (b) is unfriendly to non-x86 archs, when they get kvm ports. So fix by doing the register fixups in the kernel and passing to userspace only an abstract description of the PIO to be done. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Use the generic skip_emulated_instruction() in hypercall codeDor Laor2007-05-031-1/+1
| | | | | | | | Instead of twiddling the rip registers directly, use the skip_emulated_instruction() function to do that for us. Signed-off-by: Dor Laor <dor.laor@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: always reload segment selectorsIngo Molnar2007-03-271-16/+21
| | | | | | | | | failed VM entry on VMX might still change %fs or %gs, thus make sure that KVM always reloads the segment selectors. This is crutial on both x86 and x86_64: x86 has __KERNEL_PDA in %fs on which things like 'current' depends and x86_64 has 0 there and needs MSR_GS_BASE to work. Signed-off-by: Ingo Molnar <mingo@elte.hu>
* KVM: Prevent system selectors leaking into guest on real->protected mode ↵Avi Kivity2007-03-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | transition on vmx Intel virtualization extensions do not support virtualizing real mode. So kvm uses virtualized vm86 mode to run real mode code. Unfortunately, this virtualized vm86 mode does not support the so called "big real" mode, where the segment selector and base do not agree with each other according to the real mode rules (base == selector << 4). To work around this, kvm checks whether a selector/base pair violates the virtualized vm86 rules, and if so, forces it into conformance. On a transition back to protected mode, if we see that the guest did not touch a forced segment, we restore it back to the original protected mode value. This pile of hacks breaks down if the gdt has changed in real mode, as it can cause a segment selector to point to a system descriptor instead of a normal data segment. In fact, this happens with the Windows bootloader and the qemu acpi bios, where a protected mode memcpy routine issues an innocent 'pop %es' and traps on an attempt to load a system descriptor. "Fix" by checking if the to-be-restored selector points at a system segment, and if so, coercing it into a normal data segment. The long term solution, of course, is to abandon vm86 mode and use emulation for big real mode. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Fix guest sysenter on vmxAvi Kivity2007-03-181-4/+4
| | | | | | | | The vmx code currently treats the guest's sysenter support msrs as 32-bit values, which breaks 32-bit compat mode userspace on 64-bit guests. Fix by using the native word width of the machine. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Per-vcpu inodesAvi Kivity2007-03-041-2/+1
| | | | | | | | | | | | | | | | | | | Allocate a distinct inode for every vcpu in a VM. This has the following benefits: - the filp cachelines are no longer bounced when f_count is incremented on every ioctl() - the API and internal code are distinctly clearer; for example, on the KVM_GET_REGS ioctl, there is no need to copy the vcpu number from userspace and then copy the registers back; the vcpu identity is derived from the fd used to make the call Right now the performance benefits are completely theoretical since (a) we don't support more than one vcpu per VM and (b) virtualization hardware inefficiencies completely everwhelm any cacheline bouncing effects. But both of these will change, and we need to prepare the API today. Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Wire up hypercall handlers to a central arch-independent locationAvi Kivity2007-03-041-9/+1
| | | | Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Add host hypercall support for vmxIngo Molnar2007-03-041-0/+15
| | | | Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: add MSR based hypercall APIIngo Molnar2007-03-041-0/+13
| | | | | | | | This adds a special MSR based hypercall API to KVM. This is to be used by paravirtual kernels and virtual drivers. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: Use ARRAY_SIZE macro instead of manual calculation.Ahmed S. Darwish2007-03-041-1/+2
| | | | | | Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com> Signed-off-by: Dor Laor <dor.laor@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: vmx: hack set_cr0_no_modeswitch() to actually do modeswitchJoerg Roedel2007-03-041-0/+3
| | | | | | | | | The whole thing is rotten, but this allows vmx to boot with the guest reboot fix. Signed-off-by: Markus Rechberger <markus.rechberger@amd.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
* KVM: CosmeticsAvi Kivity2007-03-041-3/+1
| | | | Signed-off-by: Avi Kivity <avi@qumranet.com>
* [PATCH] i386: Convert i386 PDA code to use %fsJeremy Fitzhardinge2007-02-131-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | Convert the PDA code to use %fs rather than %gs as the segment for per-processor data. This is because some processors show a small but measurable performance gain for reloading a NULL segment selector (as %fs generally is in user-space) versus a non-NULL one (as %gs generally is). On modern processors the difference is very small, perhaps undetectable. Some old AMD "K6 3D+" processors are noticably slower when %fs is used rather than %gs; I have no idea why this might be, but I think they're sufficiently rare that it doesn't matter much. This patch also fixes the math emulator, which had not been adjusted to match the changed struct pt_regs. [frederik.deweerdt@gmail.com: fixit with gdb] [mingo@elte.hu: Fix KVM too] Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Ian Campbell <Ian.Campbell@XenSource.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Zachary Amsden <zach@vmware.com> Cc: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org>
* [PATCH] KVM: cpu hotplug supportAvi Kivity2007-02-121-1/+7
| | | | | | | | | | | On hotplug, we execute the hardware extension enable sequence. On unplug, we decache any vcpus that last ran on the exiting cpu, and execute the hardware extension disable sequence. Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] KVM: VMX: add vcpu_clear()Avi Kivity2007-02-121-4/+11
| | | | | | | | | | | | | | | | Like the inline code it replaces, this function decaches the vmcs from the cpu it last executed on. in addition: - vcpu_clear() works if the last cpu is also the cpu we're running on - it is faster on larger smps by virtue of using smp_call_function_single() Includes fix from Ingo Molnar. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] kvm: VMX: Reload ds and es even in 64-bit modeAvi Kivity2007-02-121-2/+0
| | | | | | | | | Or 32-bit userspace will get confused. Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] kvm: vmx: handle triple faults by returning EXIT_REASON_SHUTDOWN to ↵Avi Kivity2007-02-121-0/+6
| | | | | | | | | | | userspace Just like svm. Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] kvm: optimize inline assemblyIngo Molnar2007-02-121-6/+6
| | | | | | | | | | | Forms like "0(%rsp)" generate an instruction with an unnecessary one byte displacement under certain circumstances. replace with the equivalent "(%rsp)". Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] kvm: NULL noise removalAl Viro2007-02-091-1/+1
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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