From dd180b3e90253cb4ca95d603a8c17413f8daec69 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Sat, 3 Jul 2010 16:02:42 +0800 Subject: [PATCH] KVM: VMX: fix tlb flush with invalid root Commit 341d9b535b6c simplify reload logic while entry guest mode, it can avoid unnecessary sync-root if KVM_REQ_MMU_RELOAD and KVM_REQ_MMU_SYNC both set. But, it cause a issue that when we handle 'KVM_REQ_TLB_FLUSH', the root is invalid, it is triggered during my test: Kernel BUG at ffffffffa00212b8 [verbose debug info unavailable] ...... Fixed by directly return if the root is not ready. Signed-off-by: Xiao Guangrong Signed-off-by: Marcelo Tosatti --- arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/mmu.c | 2 -- arch/x86/kvm/vmx.c | 5 ++++- 3 files changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 50c79b9f5c3..502e53f999c 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -40,6 +40,8 @@ 0xFFFFFF0000000000ULL) #define INVALID_PAGE (~(hpa_t)0) +#define VALID_PAGE(x) ((x) != INVALID_PAGE) + #define UNMAPPED_GVA (~(gpa_t)0) /* KVM Hugepage definitions for x86 */ diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index a20fd613acf..70cdf6876b5 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -92,8 +92,6 @@ module_param(oos_shadow, bool, 0644); #define PT_FIRST_AVAIL_BITS_SHIFT 9 #define PT64_SECOND_AVAIL_BITS_SHIFT 52 -#define VALID_PAGE(x) ((x) != INVALID_PAGE) - #define PT64_LEVEL_BITS 9 #define PT64_LEVEL_SHIFT(level) \ diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 4dfb1dc09c8..2fdcc9819f3 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -1828,8 +1828,11 @@ static void exit_lmode(struct kvm_vcpu *vcpu) static void vmx_flush_tlb(struct kvm_vcpu *vcpu) { vpid_sync_context(to_vmx(vcpu)); - if (enable_ept) + if (enable_ept) { + if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) + return; ept_sync_context(construct_eptp(vcpu->arch.mmu.root_hpa)); + } } static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu) -- 2.20.1