The patch below does not apply to the 5.12-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 bc9eff67fc35d733e2de0e0017dc3f5a86e8daf8 Mon Sep 17 00:00:00 2001
From: Sean Christopherson seanjc@google.com Date: Wed, 21 Apr 2021 19:21:27 -0700 Subject: [PATCH] KVM: SVM: Use default rAX size for INVLPGA emulation
Drop bits 63:32 of RAX when grabbing the address for INVLPGA emulation outside of 64-bit mode to make KVM's emulation slightly less wrong. The address for INVLPGA is determined by the effective address size, i.e. it's not hardcoded to 64/32 bits for a given mode. Add a FIXME to call out that the emulation is wrong.
Opportunistically tweak the ASID handling to make it clear that it's defined by ECX, not rCX.
Per the APM: The portion of rAX used to form the address is determined by the effective address size (current execution mode and optional address size prefix). The ASID is taken from ECX.
Fixes: ff092385e828 ("KVM: SVM: Implement INVLPGA") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson seanjc@google.com Message-Id: 20210422022128.3464144-9-seanjc@google.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 857bcf3a4cda..1f5a8e7872c1 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -2290,11 +2290,17 @@ static int clgi_interception(struct kvm_vcpu *vcpu)
static int invlpga_interception(struct kvm_vcpu *vcpu) { - trace_kvm_invlpga(to_svm(vcpu)->vmcb->save.rip, kvm_rcx_read(vcpu), - kvm_rax_read(vcpu)); + gva_t gva = kvm_rax_read(vcpu); + u32 asid = kvm_rcx_read(vcpu); + + /* FIXME: Handle an address size prefix. */ + if (!is_long_mode(vcpu)) + gva = (u32)gva; + + trace_kvm_invlpga(to_svm(vcpu)->vmcb->save.rip, asid, gva);
/* Let's treat INVLPGA the same as INVLPG (can be optimized!) */ - kvm_mmu_invlpg(vcpu, kvm_rax_read(vcpu)); + kvm_mmu_invlpg(vcpu, gva);
return kvm_skip_emulated_instruction(vcpu); }