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| author | Avi Kivity <avi@qumranet.com> | 2007-09-14 20:26:06 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-09-14 13:59:55 -0700 |
| commit | 22d95b1282810f5af599ee292b3fc443aefbdad0 (patch) | |
| tree | dafe050aef12ea4bbac4ffb77070d8ec416a0838 /drivers/kvm | |
| parent | 44e3ff32ac229a10a30b7b840f092f5b32a5f72a (diff) | |
| download | op-kernel-dev-22d95b1282810f5af599ee292b3fc443aefbdad0.zip op-kernel-dev-22d95b1282810f5af599ee292b3fc443aefbdad0.tar.gz | |
KVM: MMU: Fix rare oops on guest context switch
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>
Diffstat (limited to 'drivers/kvm')
| -rw-r--r-- | drivers/kvm/kvm.h | 10 | ||||
| -rw-r--r-- | drivers/kvm/mmu.c | 5 |
2 files changed, 10 insertions, 5 deletions
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h index 3ac9cbc..336be86 100644 --- a/drivers/kvm/kvm.h +++ b/drivers/kvm/kvm.h @@ -619,7 +619,7 @@ unsigned long segment_base(u16 selector); void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *old, const u8 *new, int bytes); int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva); -void kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu); +void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu); int kvm_mmu_load(struct kvm_vcpu *vcpu); void kvm_mmu_unload(struct kvm_vcpu *vcpu); @@ -628,11 +628,15 @@ int kvm_hypercall(struct kvm_vcpu *vcpu, struct kvm_run *run); static inline int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t gva, u32 error_code) { - if (unlikely(vcpu->kvm->n_free_mmu_pages < KVM_MIN_FREE_MMU_PAGES)) - kvm_mmu_free_some_pages(vcpu); return vcpu->mmu.page_fault(vcpu, gva, error_code); } +static inline void kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu) +{ + if (unlikely(vcpu->kvm->n_free_mmu_pages < KVM_MIN_FREE_MMU_PAGES)) + __kvm_mmu_free_some_pages(vcpu); +} + static inline int kvm_mmu_reload(struct kvm_vcpu *vcpu) { if (likely(vcpu->mmu.root_hpa != INVALID_PAGE)) diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c index 1a87ba9..23965aa 100644 --- a/drivers/kvm/mmu.c +++ b/drivers/kvm/mmu.c @@ -273,12 +273,14 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu) int r; r = __mmu_topup_memory_caches(vcpu, GFP_NOWAIT); + kvm_mmu_free_some_pages(vcpu); if (r < 0) { spin_unlock(&vcpu->kvm->lock); kvm_arch_ops->vcpu_put(vcpu); r = __mmu_topup_memory_caches(vcpu, GFP_KERNEL); kvm_arch_ops->vcpu_load(vcpu); spin_lock(&vcpu->kvm->lock); + kvm_mmu_free_some_pages(vcpu); } return r; } @@ -1208,7 +1210,7 @@ int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) return kvm_mmu_unprotect_page(vcpu, gpa >> PAGE_SHIFT); } -void kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu) +void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu) { while (vcpu->kvm->n_free_mmu_pages < KVM_REFILL_PAGES) { struct kvm_mmu_page *page; @@ -1218,7 +1220,6 @@ void kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu) kvm_mmu_zap_page(vcpu->kvm, page); } } -EXPORT_SYMBOL_GPL(kvm_mmu_free_some_pages); static void free_mmu_pages(struct kvm_vcpu *vcpu) { |
