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path: root/drivers/kvm/kvm.h (follow)
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2007-03-04KVM: Per-vcpu inodesAvi Kivity1-1/+2
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>
2007-03-04KVM: Wire up hypercall handlers to a central arch-independent locationAvi Kivity1-0/+2
Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-03-04KVM: add MSR based hypercall APIIngo Molnar1-0/+6
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>
2007-03-04KVM: Use page_private()/set_page_private() apisMarkus Rechberger1-1/+1
Besides using an established api, this allows using kvm in older kernels. Signed-off-by: Markus Rechberger <markus.rechberger@amd.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-02-12[PATCH] KVM: cpu hotplug supportAvi Kivity1-0/+1
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>
2007-02-12[PATCH] KVM: Add a global list of all virtual machinesAvi Kivity1-0/+1
This will allow us to iterate over all vcpus and see which cpus they are running on. [akpm@osdl.org: use standard (ugly) initialisers] 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>
2007-02-12[PATCH] kvm: Fix asm constraint for lldt instructionS.Caglar Onur1-1/+1
lldt does not accept immediate operands, which "g" allows. Signed-off-by: S.Caglar Onur <caglar@pardus.org.tr> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-26[PATCH] KVM: Emulate IA32_MISC_ENABLE msrAvi Kivity1-0/+1
This allows netbsd 3.1 i386 to get further along installing. Signed-off-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-05[PATCH] KVM: MMU: Replace atomic allocations by preallocated objectsAvi Kivity1-1/+15
The mmu sometimes needs memory for reverse mapping and parent pte chains. however, we can't allocate from within the mmu because of the atomic context. So, move the allocations to a central place that can be executed before the main mmu machinery, where we can bail out on failure before any damage is done. (error handling is deffered for now, but the basic structure is there) Signed-off-by: Avi Kivity <avi@qumranet.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-05[PATCH] KVM: MMU: Never free a shadow page actively serving as a rootAvi Kivity1-0/+1
We always need cr3 to point to something valid, so if we detect that we're freeing a root page, simply push it back to the top of the active list. Signed-off-by: Avi Kivity <avi@qumranet.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-05[PATCH] KVM: MMU: Page table write flood protectionAvi Kivity1-0/+3
In fork() (or when we protect a page that is no longer a page table), we can experience floods of writes to a page, which have to be emulated. This is expensive. So, if we detect such a flood, zap the page so subsequent writes can proceed natively. Signed-off-by: Avi Kivity <avi@qumranet.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-05[PATCH] KVM: MMU: Remove invlpg interceptionAvi Kivity1-1/+0
Since we write protect shadowed guest page tables, there is no need to trap page invalidations (the guest will always change the mapping before issuing the invlpg instruction). Signed-off-by: Avi Kivity <avi@qumranet.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-05[PATCH] KVM: MMU: oom handlingAvi Kivity1-0/+12
When beginning to process a page fault, make sure we have enough shadow pages available to service the fault. If not, free some pages. Signed-off-by: Avi Kivity <avi@qumranet.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-05[PATCH] KVM: MMU: If emulating an instruction fails, try unprotecting the pageAvi Kivity1-0/+1
A page table may have been recycled into a regular page, and so any instruction can be executed on it. Unprotect the page and let the cpu do its thing. Signed-off-by: Avi Kivity <avi@qumranet.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-05[PATCH] KVM: MMU: Support emulated writes into RAMAvi Kivity1-0/+3
As the mmu write protects guest page table, we emulate those writes. Since they are not mmio, there is no need to go to userspace to perform them. So, perform the writes in the kernel if possible, and notify the mmu about them so it can take the approriate action. Signed-off-by: Avi Kivity <avi@qumranet.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-05[PATCH] KVM: MMU: Shadow page table cachingAvi Kivity1-1/+44
Define a hashtable for caching shadow page tables. Look up the cache on context switch (cr3 change) or during page faults. The key to the cache is a combination of - the guest page table frame number - the number of paging levels in the guest * we can cache real mode, 32-bit mode, pae, and long mode page tables simultaneously. this is useful for smp bootup. - the guest page table table * some kernels use a page as both a page table and a page directory. this allows multiple shadow pages to exist for that page, one per level - the "quadrant" * 32-bit mode page tables span 4MB, whereas a shadow page table spans 2MB. similarly, a 32-bit page directory spans 4GB, while a shadow page directory spans 1GB. the quadrant allows caching up to 4 shadow page tables for one guest page in one level. - a "metaphysical" bit * for real mode, and for pse pages, there is no guest page table, so set the bit to avoid write protecting the page. Signed-off-by: Avi Kivity <avi@qumranet.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-05[PATCH] KVM: MU: Special treatment for shadow pae root pagesAvi Kivity1-15/+2
Since we're not going to cache the pae-mode shadow root pages, allocate a single pae shadow that will hold the four lower-level pages, which will act as roots. Signed-off-by: Avi Kivity <avi@qumranet.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-05[PATCH] KVM: MMU: Load the pae pdptrs on cr3 change like the processor doesAvi Kivity1-0/+1
In pae mode, a load of cr3 loads the four third-level page table entries in addition to cr3 itself. Signed-off-by: Avi Kivity <avi@qumranet.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-05[PATCH] KVM: MMU: Implement simple reverse mappingAvi Kivity1-0/+1
Keep in each host page frame's page->private a pointer to the shadow pte which maps it. If there are multiple shadow ptes mapping the page, set bit 0 of page->private, and use the rest as a pointer to a linked list of all such mappings. Reverse mappings are needed because we when we cache shadow page tables, we must protect the guest page tables from being modified by the guest, as that would invalidate the cached ptes. Signed-off-by: Avi Kivity <avi@qumranet.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-05[PATCH] KVM: Prevent stale bits in cr0 and cr4Avi Kivity1-0/+1
Hardware virtualization implementations allow the guests to freely change some of the bits in cr0 and cr4, but trap when changing the other bits. This is useful to avoid excessive exits due to changing, for example, the ts flag. It also means the kvm's copy of cr0 and cr4 may be stale with respect to these bits. most of the time this doesn't matter as these bits are not very interesting. Other times, however (for example when returning cr0 to userspace), they are, so get the fresh contents of these bits from the guest by means of a new arch operation. Signed-off-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-05[PATCH] KVM: Improve interrupt responseDor Laor1-0/+4
The current interrupt injection mechanism might delay an interrupt under the following circumstances: - if injection fails because the guest is not interruptible (rflags.IF clear, or after a 'mov ss' or 'sti' instruction). Userspace can check rflags, but the other cases or not testable under the current API. - if injection fails because of a fault during delivery. This probably never happens under normal guests. - if injection fails due to a physical interrupt causing a vmexit so that it can be handled by the host. In all cases the guest proceeds without processing the interrupt, reducing the interactive feel and interrupt throughput of the guest. This patch fixes the situation by allowing userspace to request an exit when the 'interrupt window' opens, so that it can re-inject the interrupt at the right time. Guest interactivity is very visibly improved. Signed-off-by: Dor Laor <dor.laor@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-30[PATCH] kvm: fix GFP_KERNEL allocation in atomic section in kvm_dev_ioctl_create_vcpu()Ingo Molnar1-1/+2
fix an GFP_KERNEL allocation in atomic section: kvm_dev_ioctl_create_vcpu() called kvm_mmu_init(), which calls alloc_pages(), while holding the vcpu. The fix is to set up the MMU state in two phases: kvm_mmu_create() and kvm_mmu_setup(). (NOTE: free_vcpus does an kvm_mmu_destroy() call so there's no need for any extra teardown branch on allocation/init failure here.) Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-30[PATCH] KVM: Move common msr handling to arch independent codeAvi Kivity1-3/+2
Signed-off-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-30[PATCH] KVM: Simplify is_long_mode()Avi Kivity1-1/+9
Instead of doing tricky stuff with the arch dependent virtualization registers, take a peek at the guest's efer. This simlifies some code, and fixes some confusion in the mmu branch. Signed-off-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-13[PATCH] KVM: Replace __x86_64__ with CONFIG_X86_64Avi Kivity1-4/+4
As per akpm's request. Signed-off-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10[PATCH] kvm: userspace interfaceAvi Kivity1-0/+551
web site: http://kvm.sourceforge.net mailing list: kvm-devel@lists.sourceforge.net (http://lists.sourceforge.net/lists/listinfo/kvm-devel) The following patchset adds a driver for Intel's hardware virtualization extensions to the x86 architecture. The driver adds a character device (/dev/kvm) that exposes the virtualization capabilities to userspace. Using this driver, a process can run a virtual machine (a "guest") in a fully virtualized PC containing its own virtual hard disks, network adapters, and display. Using this driver, one can start multiple virtual machines on a host. Each virtual machine is a process on the host; a virtual cpu is a thread in that process. kill(1), nice(1), top(1) work as expected. In effect, the driver adds a third execution mode to the existing two: we now have kernel mode, user mode, and guest mode. Guest mode has its own address space mapping guest physical memory (which is accessible to user mode by mmap()ing /dev/kvm). Guest mode has no access to any I/O devices; any such access is intercepted and directed to user mode for emulation. The driver supports i386 and x86_64 hosts and guests. All combinations are allowed except x86_64 guest on i386 host. For i386 guests and hosts, both pae and non-pae paging modes are supported. SMP hosts and UP guests are supported. At the moment only Intel hardware is supported, but AMD virtualization support is being worked on. Performance currently is non-stellar due to the naive implementation of the mmu virtualization, which throws away most of the shadow page table entries every context switch. We plan to address this in two ways: - cache shadow page tables across tlb flushes - wait until AMD and Intel release processors with nested page tables Currently a virtual desktop is responsive but consumes a lot of CPU. Under Windows I tried playing pinball and watching a few flash movies; with a recent CPU one can hardly feel the virtualization. Linux/X is slower, probably due to X being in a separate process. In addition to the driver, you need a slightly modified qemu to provide I/O device emulation and the BIOS. Caveats (akpm: might no longer be true): - The Windows install currently bluescreens due to a problem with the virtual APIC. We are working on a fix. A temporary workaround is to use an existing image or install through qemu - Windows 64-bit does not work. That's also true for qemu, so it's probably a problem with the device model. [bero@arklinux.org: build fix] [simon.kagstrom@bth.se: build fix, other fixes] [uril@qumranet.com: KVM: Expose interrupt bitmap] [akpm@osdl.org: i386 build fix] [mingo@elte.hu: i386 fixes] [rdreier@cisco.com: add log levels to all printks] [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings] [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support] Signed-off-by: Yaniv Kamay <yaniv@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com> Cc: Simon Kagstrom <simon.kagstrom@bth.se> Cc: Bernhard Rosenkraenzer <bero@arklinux.org> Signed-off-by: Uri Lublin <uril@qumranet.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Anthony Liguori <anthony@codemonkey.ws> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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