From 0fe998b295a37234392072c23e22b8bba4774d0f Mon Sep 17 00:00:00 2001 From: Jim Mattson Date: Fri, 4 Jun 2021 10:26:05 -0700 Subject: [PATCH] KVM: nVMX: Fail on MMIO completion for nested posted interrupts When the kernel has no mapping for the vmcs02 virtual APIC page, userspace MMIO completion is necessary to process nested posted interrupts. This is not a configuration that KVM supports. Rather than silently ignoring the problem, try to exit to userspace with KVM_INTERNAL_ERROR. Note that the event that triggers this error is consumed as a side-effect of a call to kvm_check_nested_events. On some paths (notably through kvm_vcpu_check_block), the error is dropped. In any case, this is an incremental improvement over always ignoring the error. Signed-off-by: Jim Mattson Message-Id: <20210604172611.281819-7-jmattson@google.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/nested.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 73f63ad06366..4e545996440b 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -3707,7 +3707,7 @@ static int vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu) if (max_irr != 256) { vapic_page = vmx->nested.virtual_apic_map.hva; if (!vapic_page) - return 0; + goto mmio_needed; __kvm_apic_update_irr(vmx->nested.pi_desc->pir, vapic_page, &max_irr); @@ -3721,6 +3721,10 @@ static int vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu) nested_mark_vmcs12_pages_dirty(vcpu); return 0; + +mmio_needed: + kvm_handle_memory_failure(vcpu, X86EMUL_IO_NEEDED, NULL); + return -ENXIO; } static void nested_vmx_inject_exception_vmexit(struct kvm_vcpu *vcpu, -- 2.11.0