The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f66c53b3b94f658590e1012bf6d922f8b7e01bda Mon Sep 17 00:00:00 2001
From: Sean Christopherson seanjc@google.com Date: Thu, 4 Mar 2021 17:10:58 -0800 Subject: [PATCH] KVM: x86: Defer the MMU unload to the normal path on an global INVPCID
Defer unloading the MMU after a INVPCID until the instruction emulation has completed, i.e. until after RIP has been updated.
On VMX, this is a benign bug as VMX doesn't touch the MMU when skipping an emulated instruction. However, on SVM, if nrip is disabled, the emulator is used to skip an instruction, which would lead to fireworks if the emulator were invoked without a valid MMU.
Fixes: eb4b248e152d ("kvm: vmx: Support INVPCID in shadow paging mode") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson seanjc@google.com Message-Id: 20210305011101.3597423-15-seanjc@google.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 3ef64959a443..5c235b4dd74e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -11504,7 +11504,7 @@ int kvm_handle_invpcid(struct kvm_vcpu *vcpu, unsigned long type, gva_t gva)
fallthrough; case INVPCID_TYPE_ALL_INCL_GLOBAL: - kvm_mmu_unload(vcpu); + kvm_make_request(KVM_REQ_MMU_RELOAD, vcpu); return kvm_skip_emulated_instruction(vcpu);
default: