From 690908104e39d37947f89d76388c876ce4ec5fda Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 15 Apr 2019 15:16:17 +0200 Subject: KVM: nVMX: allow tests to use bad virtual-APIC page address As mentioned in the comment, there are some special cases where we can simply clear the TPR shadow bit from the CPU-based execution controls in the vmcs02. Handle them so that we can remove some XFAILs from vmx.flat. Signed-off-by: Paolo Bonzini --- arch/x86/kvm/vmx/nested.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) (limited to 'arch/x86/kvm/vmx/nested.c') diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 7ec9bb1dd723..a22af5a85540 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2873,20 +2873,27 @@ static void nested_get_vmcs12_pages(struct kvm_vcpu *vcpu) /* * If translation failed, VM entry will fail because * prepare_vmcs02 set VIRTUAL_APIC_PAGE_ADDR to -1ull. - * Failing the vm entry is _not_ what the processor - * does but it's basically the only possibility we - * have. We could still enter the guest if CR8 load - * exits are enabled, CR8 store exits are enabled, and - * virtualize APIC access is disabled; in this case - * the processor would never use the TPR shadow and we - * could simply clear the bit from the execution - * control. But such a configuration is useless, so - * let's keep the code simple. */ if (!is_error_page(page)) { vmx->nested.virtual_apic_page = page; hpa = page_to_phys(vmx->nested.virtual_apic_page); vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, hpa); + } else if (nested_cpu_has(vmcs12, CPU_BASED_CR8_LOAD_EXITING) && + nested_cpu_has(vmcs12, CPU_BASED_CR8_STORE_EXITING) && + !nested_cpu_has2(vmcs12, SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES)) { + /* + * The processor will never use the TPR shadow, simply + * clear the bit from the execution control. Such a + * configuration is useless, but it happens in tests. + * For any other configuration, failing the vm entry is + * _not_ what the processor does but it's basically the + * only possibility we have. + */ + vmcs_clear_bits(CPU_BASED_VM_EXEC_CONTROL, + CPU_BASED_TPR_SHADOW); + } else { + printk("bad virtual-APIC page address\n"); + dump_vmcs(); } } -- cgit v1.2.3