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* KVM: MMU: Remove user access when allowing kernel access to gpte.w=0 pageAvi Kivity2010-06-091-0/+3
| | | | | | | | | | If cr0.wp=0, we have to allow the guest kernel access to a page with pte.w=0. We do that by setting spte.w=1, since the host cr0.wp must remain set so the host can write protect pages. Once we allow write access, we must remove user access otherwise we mistakenly allow the user to write the page. Reviewed-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: invalidate and flush on spte small->large page size changeMarcelo Tosatti2010-06-091-0/+2
| | | | | | | | | | | | | | | | Always invalidate spte and flush TLBs when changing page size, to make sure different sized translations for the same address are never cached in a CPU's TLB. Currently the only case where this occurs is when a non-leaf spte pointer is overwritten by a leaf, large spte entry. This can happen after dirty logging is disabled on a memslot, for example. Noticed by Andrea. KVM-Stable-Tag Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: Segregate shadow pages with different cr0.wpAvi Kivity2010-05-191-1/+2
| | | | | | | | | | | | When cr0.wp=0, we may shadow a gpte having u/s=1 and r/w=0 with an spte having u/s=0 and r/w=1. This allows excessive access if the guest sets cr0.wp=1 and accesses through this spte. Fix by making cr0.wp part of the base role; we'll have different sptes for the two cases and the problem disappears. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: MMU: Don't read pdptrs with mmu spinlock held in mmu_alloc_rootsAvi Kivity2010-05-191-0/+7
| | | | | | | | | | On svm, kvm_read_pdptr() may require reading guest memory, which can sleep. Push the spinlock into mmu_alloc_roots(), and only take it after we've read the pdptr. Tested-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: move unsync/sync tracpoints to proper placeXiao Guangrong2010-05-191-2/+2
| | | | | | | | Move unsync/sync tracepoints to the proper place, it's good for us to obtain unsync page live time Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Fix mmu shrinker errorGui Jianfeng2010-05-191-5/+5
| | | | | | | | | kvm_mmu_remove_one_alloc_mmu_page() assumes kvm_mmu_zap_page() only reclaims only one sp, but that's not the case. This will cause mmu shrinker returns a wrong number. This patch fix the counting error. Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: MMU: fix hashing for TDP and non-paging modesEric Northup2010-05-191-4/+8
| | | | | | | | | For TDP mode, avoid creating multiple page table roots for the single guest-to-host physical address map by fixing the inputs used for the shadow page table hash in mmu_alloc_roots(). Signed-off-by: Eric Northup <digitaleric@google.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: MMU: cleanup for function unaccount_shadowed()Wei Yongjun2010-05-171-1/+1
| | | | | | | | | Since gfn is not changed in the for loop, we do not need to call gfn_to_memslot_unaliased() under the loop, and it is safe to move it out. Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Get rid of dead function gva_to_page()Gui Jianfeng2010-05-171-14/+0
| | | | | | | Nobody use gva_to_page() anymore, get rid of it. Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: Remove unused varialbe in rmap_next()Gui Jianfeng2010-05-171-2/+0
| | | | | | | Remove unused varialbe in rmap_next() Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: use the correct RCU API for PROVE_RCU=yLai Jiangshan2010-05-171-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The RCU/SRCU API have already changed for proving RCU usage. I got the following dmesg when PROVE_RCU=y because we used incorrect API. This patch coverts rcu_deference() to srcu_dereference() or family API. =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- arch/x86/kvm/mmu.c:3020 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by qemu-system-x86/8550: #0: (&kvm->slots_lock){+.+.+.}, at: [<ffffffffa011a6ac>] kvm_set_memory_region+0x29/0x50 [kvm] #1: (&(&kvm->mmu_lock)->rlock){+.+...}, at: [<ffffffffa012262d>] kvm_arch_commit_memory_region+0xa6/0xe2 [kvm] stack backtrace: Pid: 8550, comm: qemu-system-x86 Not tainted 2.6.34-rc4-tip-01028-g939eab1 #27 Call Trace: [<ffffffff8106c59e>] lockdep_rcu_dereference+0xaa/0xb3 [<ffffffffa012f6c1>] kvm_mmu_calculate_mmu_pages+0x44/0x7d [kvm] [<ffffffffa012263e>] kvm_arch_commit_memory_region+0xb7/0xe2 [kvm] [<ffffffffa011a5d7>] __kvm_set_memory_region+0x636/0x6e2 [kvm] [<ffffffffa011a6ba>] kvm_set_memory_region+0x37/0x50 [kvm] [<ffffffffa015e956>] vmx_set_tss_addr+0x46/0x5a [kvm_intel] [<ffffffffa0126592>] kvm_arch_vm_ioctl+0x17a/0xcf8 [kvm] [<ffffffff810a8692>] ? unlock_page+0x27/0x2c [<ffffffff810bf879>] ? __do_fault+0x3a9/0x3e1 [<ffffffffa011b12f>] kvm_vm_ioctl+0x364/0x38d [kvm] [<ffffffff81060cfa>] ? up_read+0x23/0x3d [<ffffffff810f3587>] vfs_ioctl+0x32/0xa6 [<ffffffff810f3b19>] do_vfs_ioctl+0x495/0x4db [<ffffffff810e6b2f>] ? fget_light+0xc2/0x241 [<ffffffff810e416c>] ? do_sys_open+0x104/0x116 [<ffffffff81382d6d>] ? retint_swapgs+0xe/0x13 [<ffffffff810f3ba6>] sys_ioctl+0x47/0x6a [<ffffffff810021db>] system_call_fastpath+0x16/0x1b Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: cleanup for hlist walk restartXiao Guangrong2010-05-171-5/+10
| | | | | | | | | | Quote from Avi: |Just change the assignment to a 'goto restart;' please, |I don't like playing with list_for_each internals. Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: MMU: remove unused parameter in mmu_parent_walk()Xiao Guangrong2010-05-171-13/+11
| | | | | | | 'vcpu' is unused, remove it Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: MMU: remove unused struct kvm_unsync_walkXiao Guangrong2010-05-171-5/+0
| | | | | | | Remove 'struct kvm_unsync_walk' since it's not used. Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: MMU: Replace role.glevels with role.cr4_paeAvi Kivity2010-05-171-6/+6
| | | | | | | | | | | | | There is no real distinction between glevels=3 and glevels=4; both have exactly the same format and the code is treated exactly the same way. Drop role.glevels and replace is with role.cr4_pae (which is meaningful). This simplifies the code a bit. As a side effect, it allows sharing shadow page tables between pae and longmode guest page tables at the same guest page. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: MMU: remove unused fieldXiao Guangrong2010-05-171-1/+0
| | | | | | | kvm_mmu_page.oos_link is not used, so remove it Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: MMU: cleanup/fix mmu audit codeXiao Guangrong2010-05-171-7/+8
| | | | | | | | | | This patch does: - 'sp' parameter in inspect_spte_fn() is not used, so remove it - fix 'kvm' and 'slots' is not defined in count_rmaps() - fix a bug in inspect_spte_has_rmap() Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: MMU: Disassociate direct maps from guest levelsAvi Kivity2010-05-171-0/+2
| | | | | | | | | | | | Direct maps are linear translations for a section of memory, used for real mode or with large pages. As such, they are independent of the guest levels. Teach the mmu about this by making page->role.glevels = 0 for direct maps. This allows direct maps to be shared among real mode and the various paging modes. Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: check reserved bits only if CR4.PSE=1 or CR4.PAE=1Xiao Guangrong2010-05-171-3/+9
| | | | | | | | | - Check reserved bits only if CR4.PAE=1 or CR4.PSE=1 when guest #PF occurs - Fix a typo in reset_rsvds_bits_mask() Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: Reinstate pte prefetch on invlpgAvi Kivity2010-05-171-14/+23
| | | | | | | | | | | | | | | | | | | | Commit fb341f57 removed the pte prefetch on guest invlpg, citing guest races. However, the SDM is adamant that prefetch is allowed: "The processor may create entries in paging-structure caches for translations required for prefetches and for accesses that are a result of speculative execution that would never actually occur in the executed code path." And, in fact, there was a race in the prefetch code: we picked up the pte without the mmu lock held, so an older invlpg could install the pte over a newer invlpg. Reinstate the prefetch logic, but this time note whether another invlpg has executed using a counter. If a race occured, do not install the pte. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: MMU: Consolidate two guest pte reads in kvm_mmu_pte_write()Avi Kivity2010-05-171-38/+31
| | | | | | | | | | kvm_mmu_pte_write() reads guest ptes in two different occasions, both to allow a 32-bit pae guest to update a pte with 4-byte writes. Consolidate these into a single read, which also allows us to consolidate another read from an invlpg speculating a gpte into the shadow page table. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: remove redundant initialization of page->privateMinchan Kim2010-05-171-1/+0
| | | | | | | | | The prep_new_page() in page allocator calls set_page_private(page, 0). So we don't need to reinitialize private of page. Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Cc: Avi Kivity<avi@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: cleanup kvm traceXiao Guangrong2010-05-171-1/+0
| | | | | | | | | | | | This patch does: - no need call tracepoint_synchronize_unregister() when kvm module is unloaded since ftrace can handle it - cleanup ftrace's macro Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: fix kvm_mmu_zap_page() and its calling pathXiao Guangrong2010-04-201-4/+7
| | | | | | | | | | | | This patch fix: - calculate zapped page number properly in mmu_zap_unsync_children() - calculate freeed page number properly kvm_mmu_change_mmu_pages() - if zapped children page it shoud restart hlist walking KVM-Stable-Tag. Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* KVM: x86 emulator: fix memory access during x86 emulationGleb Natapov2010-03-011-10/+7
| | | | | | | | | | | Currently when x86 emulator needs to access memory, page walk is done with broadest permission possible, so if emulated instruction was executed by userspace process it can still access kernel memory. Fix that by providing correct memory access to page walker during emulation. Signed-off-by: Gleb Natapov <gleb@redhat.com> Cc: stable@kernel.org Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: Add tracepoint for guest page agingAvi Kivity2010-03-011-3/+8
| | | | Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: VMX: emulate accessed bit for EPTRik van Riel2010-03-011-2/+8
| | | | | | | | | | | | | | | | | | | Currently KVM pretends that pages with EPT mappings never got accessed. This has some side effects in the VM, like swapping out actively used guest pages and needlessly breaking up actively used hugepages. We can avoid those very costly side effects by emulating the accessed bit for EPT PTEs, which should only be slightly costly because pages pass through page_referenced infrequently. TLB flushing is taken care of by kvm_mmu_notifier_clear_flush_young(). This seems to help prevent KVM guests from being swapped out when they should not on my system. Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Introduce kvm_host_page_sizeJoerg Roedel2010-03-011-16/+2
| | | | | | | | | | This patch introduces a generic function to find out the host page size for a given gfn. This function is needed by the kvm iommu code. This patch also simplifies the x86 host_mapping_level function. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: Remove some useless code from alloc_mmu_pages()Wei Yongjun2010-03-011-5/+2
| | | | | | | | | If we fail to alloc page for vcpu->arch.mmu.pae_root, call to free_mmu_pages() is unnecessary, which just do free the page malloc for vcpu->arch.mmu.pae_root. Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Rename vcpu->shadow_efer to eferAvi Kivity2010-03-011-1/+1
| | | | | | | None of the other registers have the shadow_ prefix. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Move cr0/cr4/efer related helpers to x86.hAvi Kivity2010-03-011-0/+1
| | | | | | | They have more general scope than the mmu. Signed-off-by: Avi Kivity <avi@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: rename is_writeble_pte() to is_writable_pte()Takuya Yoshikawa2010-03-011-9/+9
| | | | | | | | | | | | | | There are two spellings of "writable" in arch/x86/kvm/mmu.c and paging_tmpl.h . This patch renames is_writeble_pte() to is_writable_pte() and makes grepping easy. New name is consistent with the definition of itself: return pte & PT_WRITABLE_MASK; Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Replace read accesses of vcpu->arch.cr0 by an accessorAvi Kivity2010-03-011-1/+1
| | | | | | | Since we'd like to allow the guest to own a few bits of cr0 at times, we need to know when we access those bits. Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: VMX: Enable EPT 1GB page supportSheng Yang2010-03-011-3/+5
| | | | | Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: x86: Moving PT_*_LEVEL to mmu.hSheng Yang2010-03-011-4/+0
| | | | | | | We can use them in x86.c and vmx.c now... Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: switch vcpu context to use SRCUMarcelo Tosatti2010-03-011-4/+3
| | | | Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: introduce kvm->srcu and convert kvm_set_memory_region to SRCU updateMarcelo Tosatti2010-03-011-14/+14
| | | | | | | | | | Use two steps for memslot deletion: mark the slot invalid (which stops instantiation of new shadow pages for that slot, but allows destruction), then instantiate the new empty slot. Also simplifies kvm_handle_hva locking. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: modify memslots layout in struct kvmMarcelo Tosatti2010-03-011-5/+6
| | | | | | | | | Have a pointer to an allocated region inside struct kvm. [alex: fix ppc book 3s] Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: MMU: Report spte not found in rmap before BUG()Avi Kivity2010-03-011-0/+1
| | | | | | | In the past we've had errors of single-bit in the other two cases; the printk() may confirm it for the third case (many->many). Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: x86: Fix host_mapping_level()Sheng Yang2010-01-251-4/+2
| | | | | | | | | | When found a error hva, should not return PAGE_SIZE but the level... Also clean up the coding style of the following loop. Cc: stable@kernel.org Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Allow internal errors reported to userspace to carry extra dataAvi Kivity2009-12-031-0/+1
| | | | | | | | | Usually userspace will freeze the guest so we can inspect it, but some internal state is not available. Add extra data to internal error reporting so we can expose it to the debugger. Extra data is specific to the suberror. Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: Don't pass kvm_run argumentsAvi Kivity2009-12-031-1/+1
| | | | | | They're just copies of vcpu->run, which is readily accessible. Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: fix pointer castFrederik Deweerdt2009-10-161-6/+10
| | | | | | | | | | | | | | | | On a 32 bits compile, commit 3da0dd433dc399a8c0124d0614d82a09b6a49bce introduced the following warnings: arch/x86/kvm/mmu.c: In function ‘kvm_set_pte_rmapp’: arch/x86/kvm/mmu.c:770: warning: cast to pointer from integer of different size arch/x86/kvm/mmu.c: In function ‘kvm_set_spte_hva’: arch/x86/kvm/mmu.c:849: warning: cast from pointer to integer of different size The following patch uses 'unsigned long' instead of u64 to match the pointer size on both arches. Signed-off-by: Frederik Deweerdt <frederik.deweerdt@xprog.eu> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: add support for change_pte mmu notifiersIzik Eidus2009-10-041-9/+53
| | | | | | | | | | this is needed for kvm if it want ksm to directly map pages into its shadow page tables. [marcelo: cast pfn assignment to u64] Signed-off-by: Izik Eidus <ieidus@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: MMU: add SPTE_HOST_WRITEABLE flag to the shadow ptesIzik Eidus2009-10-041-4/+11
| | | | | | | | | | | this flag notify that the host physical page we are pointing to from the spte is write protected, and therefore we cant change its access to be write unless we run get_user_pages(write = 1). (this is needed for change_pte support in kvm) Signed-off-by: Izik Eidus <ieidus@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: MMU: dont hold pagecount reference for mapped sptes pagesIzik Eidus2009-10-041-5/+2
| | | | | | | | | | | | | | | | | When using mmu notifiers, we are allowed to remove the page count reference tooken by get_user_pages to a specific page that is mapped inside the shadow page tables. This is needed so we can balance the pagecount against mapcount checking. (Right now kvm increase the pagecount and does not increase the mapcount when mapping page into shadow page table entry, so when comparing pagecount against mapcount, you have no reliable result.) Signed-off-by: Izik Eidus <ieidus@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
* KVM: Optimize kvm_mmu_unprotect_page_virt() for tdpAvi Kivity2009-09-101-0/+3
| | | | | | | We know no pages are protected, so we can short-circuit the whole thing (including fairly nasty guest memory accesses). Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: fix bogus alloc_mmu_pages assignmentMarcelo Tosatti2009-09-101-8/+0
| | | | | | | | | | | Remove the bogus n_free_mmu_pages assignment from alloc_mmu_pages. It breaks accounting of mmu pages, since n_free_mmu_pages is modified but the real number of pages remains the same. Cc: stable@kernel.org Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
* KVM: MMU: make __kvm_mmu_free_some_pages handle empty listIzik Eidus2009-09-101-1/+2
| | | | | | | | | | First check if the list is empty before attempting to look at list entries. Cc: stable@kernel.org Signed-off-by: Izik Eidus <ieidus@redhat.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
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