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path: root/drivers/kvm/mmu.c
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2008-01-30KVM: MMU: mark pages that were inserted to the shadow pages table as accessedIzik Eidus
Mark guest pages as accessed when removed from the shadow page tables for better lru processing. Signed-off-by: Izik Eidus <izike@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Rename 'release_page'Avi Kivity
Rename the awkwardly named variable. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Rename variables of type 'struct kvm_mmu_page *'Avi Kivity
These are traditionally named 'page', but even more traditionally, that name is reserved for variables that point to a 'struct page'. Rename them to 'sp' (for "shadow page"). Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Remove gpa_to_hpa()Avi Kivity
Converting last uses along the way. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Remove gva_to_hpa()Avi Kivity
No longer used. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Simplify nonpaging_map()Avi Kivity
Instead of passing an hpa, pass a regular struct page. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Adjust page_header_update_slot() to accept a gfn instead of a gpaAvi Kivity
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Remove extra gaddr parameter from set_pte_common()Avi Kivity
Similar information is available in the gfn parameter, so use that. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Move pse36 handling to the guest walkerAvi Kivity
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Don't bother the mmu if cr3 load doesn't change cr3Avi Kivity
If the guest requests just a tlb flush, don't take the vm lock and drop the mmu context pointlessly. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Avoid unnecessary remote tlb flushes when guest updates a pteAvi Kivity
If all we're doing is increasing permissions on a pte (typical for demand paging), then there's not need to flush remote tlbs. Worst case they'll get a spurious page fault. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Recalculate mmu pages needed for every memory region changeZhang Xiantao
Instead of incrementally changing the mmu cache size for every memory slot operation, recalculate it from scratch. This is simpler and safer. Signed-off-by: Zhang Xiantao <xiantao.zhang@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Selectively set PageDirty when releasing guest memoryIzik Eidus
Improve dirty bit setting for pages that kvm release, until now every page that we released we marked dirty, from now only pages that have potential to get dirty we mark dirty. Signed-off-by: Izik Eidus <izike@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Fix potential memory leak with smp real-modeIzik Eidus
When we map a page, we check whether some other vcpu mapped it for us and if so, bail out. But we should decrease the refcount on the page as we do so. Signed-off-by: Izik Eidus <izike@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Add some mmu statisticsAvi Kivity
Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Topup the mmu memory preallocation caches before emulating an insnAvi Kivity
Emulation may cause a shadow pte to be instantiated, which requires memory resources. Make sure the caches are filled to avoid an oops. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Move page fault processing to common codeAvi Kivity
The code that dispatches the page fault and emulates if we failed to map is duplicated across vmx and svm. Merge it to simplify further bugfixing. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Portability: Split kvm_vcpu into arch dependent and independent parts ↵Zhang Xiantao
(part 1) First step to split kvm_vcpu. Currently, we just use an macro to define the common fields in kvm_vcpu for all archs, and all archs need to define its own kvm_vcpu struct. Signed-off-by: Zhang Xiantao <xiantao.zhang@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Partial swapping of guest memoryIzik Eidus
This allows guest memory to be swapped. Pages which are currently mapped via shadow page tables are pinned into memory, but all other pages can be freely swapped. The patch makes gfn_to_page() elevate the page's reference count, and introduces kvm_release_page() that pairs with it. Signed-off-by: Izik Eidus <izike@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Make gfn_to_page() always safeIzik Eidus
In case the page is not present in the guest memory map, return a dummy page the guest can scribble on. This simplifies error checking in its users. Signed-off-by: Izik Eidus <izike@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Keep a reverse mapping of non-writable translationsIzik Eidus
The current kvm mmu only reverse maps writable translation. This is used to write-protect a page in case it becomes a pagetable. But with swapping support, we need a reverse mapping of read-only pages as well: when we evict a page, we need to remove any mapping to it, whether writable or not. Signed-off-by: Izik Eidus <izike@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Add rmap_next(), a helper for walking kvm rmapsIzik Eidus
Signed-off-by: Izik Eidus <izike@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Instantiate real-mode shadows as user writable shadowsAvi Kivity
This is consistent with real-mode permissions. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Move guest pte dirty bit management to the guest pagetable walkerAvi Kivity
This is more consistent with the accessed bit management, and makes the dirty bit available earlier for other purposes. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: More struct kvm_vcpu -> struct kvm cleanupsAnthony Liguori
This time, the biggest change is gpa_to_hpa. The translation of GPA to HPA does not depend on the VCPU state unlike GVA to GPA so there's no need to pass in the kvm_vcpu. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Clean up MMU functions to take struct kvm when appropriateAnthony Liguori
Some of the MMU functions take a struct kvm_vcpu even though they affect all VCPUs. This patch cleans up some of them to instead take a struct kvm. This makes things a bit more clear. The main thing that was confusing me was whether certain functions need to be called on all VCPUs. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: CodingStyle cleanupMike Day
Signed-off-by: Mike D. Day <ncmike@ncultra.org> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Allow dynamic allocation of the mmu shadow cache sizeIzik Eidus
The user is now able to set how many mmu pages will be allocated to the guest. Signed-off-by: Izik Eidus <izike@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Remove the usage of page->private field by rmapIzik Eidus
When kvm uses user-allocated pages in the future for the guest, we won't be able to use page->private for rmap, since page->rmap is reserved for the filesystem. So we move the rmap base pointers to the memory slot. A side effect of this is that we need to store the gfn of each gpte in the shadow pages, since the memory slot is addressed by gfn, instead of hfn like struct page. Signed-off-by: Izik Eidus <izik@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: MMU: Make flooding detection work when guest page faults are bypassedAvi Kivity
When we allow guest page faults to reach the guests directly, we lose the fault tracking which allows us to detect demand paging. So we provide an alternate mechnism by clearing the accessed bit when we set a pte, and checking it later to see if the guest actually used it. Signed-off-by: Avi Kivity <avi@qumranet.com>
2008-01-30KVM: Allow not-present guest page faults to bypass kvmAvi Kivity
There are two classes of page faults trapped by kvm: - host page faults, where the fault is needed to allow kvm to install the shadow pte or update the guest accessed and dirty bits - guest page faults, where the guest has faulted and kvm simply injects the fault back into the guest to handle The second class, guest page faults, is pure overhead. We can eliminate some of it on vmx using the following evil trick: - when we set up a shadow page table entry, if the corresponding guest pte is not present, set up the shadow pte as not present - if the guest pte _is_ present, mark the shadow pte as present but also set one of the reserved bits in the shadow pte - tell the vmx hardware not to trap faults which have the present bit clear With this, normal page-not-present faults go directly to the guest, bypassing kvm entirely. Unfortunately, this trick only works on Intel hardware, as AMD lacks a way to discriminate among page faults based on error code. It is also a little risky since it uses reserved bits which might become unreserved in the future, so a module parameter is provided to disable it. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-22KVM: VMX: Reset mmu context when entering real modeEddie Dong
Resetting an SMP guest will force AP enter real mode (RESET) with paging enabled in protected mode. While current enter_rmode() can only handle mode switch from nonpaging mode to real mode which leads to SMP reboot failure. Fix by reloading the mmu context on entering real mode. Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com> Signed-off-by: Qing He <qing.he@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-22KVM: MMU: Set shadow pte atomically in mmu_pte_write_zap_pte()Izik Eidus
Setting shadow page table entry should be set atomicly using set_shadow_pte(). Signed-off-by: Izik Eidus <izike@qumranet.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13KVM: MMU: Don't do GFP_NOWAIT allocationsAvi Kivity
Before preempt notifiers, kvm needed to allocate memory with GFP_NOWAIT so as not to have to enable preemption and take a heavyweight exit. On oom, we'd fall back to a GFP_KERNEL allocation. With preemption notifiers, we can do a GFP_KERNEL allocation, and perform the heavyweight exit only if the kernel decides to put us to sleep. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13KVM: Rename kvm_arch_ops to kvm_x86_opsChristian Ehrhardt
This patch just renames the current (misnamed) _arch namings to _x86 to ensure better readability when a real arch layer takes place. Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13KVM: Convert vm lock to a mutexShaohua Li
This allows the kvm mmu to perform sleepy operations, such as memory allocation. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13KVM: Use the scheduler preemption notifiers to make kvm preemptibleAvi Kivity
Current kvm disables preemption while the new virtualization registers are in use. This of course is not very good for latency sensitive workloads (one use of virtualization is to offload user interface and other latency insensitive stuff to a container, so that it is easier to analyze the remaining workload). This patch re-enables preemption for kvm; preemption is now only disabled when switching the registers in and out, and during the switch to guest mode and back. Contains fixes from Shaohua Li <shaohua.li@intel.com>. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13KVM: Move gfn_to_page out of kmap/unmap pairsShaohua Li
gfn_to_page might sleep with swap support. Move it out of the kmap calls. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-10-13KVM: Trivial: Use standard CR0 flags macros from asm/cpu-features.hRusty Russell
The kernel now has asm/cpu-features.h: use those macros instead of inventing our own. Also spell out definition of CR0_RESEVED_BITS (no code change) and fix typo. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-09-14KVM: MMU: Fix rare oops on guest context switchAvi Kivity
A guest context switch to an uncached cr3 can require allocation of shadow pages, but we only recycle shadow pages in kvm_mmu_page_fault(). Move shadow page recycling to mmu_topup_memory_caches(), which is called from both the page fault handler and from guest cr3 reload. Signed-off-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-20KVM: MMU: Fix cleaning up the shadow page allocation cacheAvi Kivity
__free_page() wants a struct page, not a virtual address. Signed-off-by: Avi Kivity <avi@qumranet.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-20KVM: MMU: Fix oopses with SLUBAvi Kivity
The kvm mmu uses page->private on shadow page tables; so does slub, and an oops result. Fix by allocating regular pages for shadows instead of using slub. Tested-by: S.Çağlar Onur <caglar@pardus.org.tr> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-20KVM: Fix memory slot management functions for guest smpAvi Kivity
The memory slot management functions were oriented against vcpu 0, where they should be kvm-wide. This causes hangs starting X on guest smp. Fix by making the functions (and resultant tail in the mmu) non-vcpu-specific. Unfortunately this reduces the efficiency of the mmu object cache a bit. We may have to revisit this later. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-20mm: Remove slab destructors from kmem_cache_create().Paul Mundt
Slab destructors were no longer supported after Christoph's c59def9f222d44bb7e2f0a559f2906191a0862d7 change. They've been BUGs for both slab and slub, and slob never supported them either. This rips out support for the dtor pointer from kmem_cache_create() completely and fixes up every single callsite in the kernel (there were about 224, not including the slab allocator definitions themselves, or the documentation references). Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2007-07-16KVM: Clean up #includesAvi Kivity
Remove unnecessary ones, and rearange the remaining in the standard order. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: MMU: Fix Wrong tlb flush orderShaohua Li
Need to flush the tlb after updating a pte, not before. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Flush remote tlbs when reducing shadow pte permissionsAvi Kivity
When a vcpu causes a shadow tlb entry to have reduced permissions, it must also clear the tlb on remote vcpus. We do that by: - setting a bit on the vcpu that requests a tlb flush before the next entry - if the vcpu is currently executing, we send an ipi to make sure it exits before we continue Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Fix vcpu freeing for guest smpAvi Kivity
A vcpu can pin up to four mmu shadow pages, which means the freeing loop will never terminate. Fix by first unpinning shadow pages on all vcpus, then freeing shadow pages. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: Lazy guest cr3 switchingAvi Kivity
Switch guest paging context may require us to allocate memory, which might fail. Instead of wiring up error paths everywhere, make context switching lazy and actually do the switch before the next guest entry, where we can return an error if allocation fails. Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-07-16KVM: MMU: Remove unused large page markerAvi Kivity
This has not been used for some time, as the same information is available in the page header. Signed-off-by: Avi Kivity <avi@qumranet.com>