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authorMaxim Levitsky <mlevitsk@redhat.com>2020-11-01 12:55:23 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2020-11-08 10:41:28 +0100
commitcc4cb017678aa66d3fb4501b2f7424ed28fc7f4d (patch)
tree180be18d38d5d1c69701a518afa7d1c65e3c053d /arch/x86/kvm/x86.h
parentKVM: Documentation: Update entry for KVM_CAP_ENFORCE_PV_CPUID (diff)
downloadlinux-cc4cb017678aa66d3fb4501b2f7424ed28fc7f4d.tar.xz
linux-cc4cb017678aa66d3fb4501b2f7424ed28fc7f4d.zip
KVM: x86: use positive error values for msr emulation that causes #GP
Recent introduction of the userspace msr filtering added code that uses negative error codes for cases that result in either #GP delivery to the guest, or handled by the userspace msr filtering. This breaks an assumption that a negative error code returned from the msr emulation code is a semi-fatal error which should be returned to userspace via KVM_RUN ioctl and usually kill the guest. Fix this by reusing the already existing KVM_MSR_RET_INVALID error code, and by adding a new KVM_MSR_RET_FILTERED error code for the userspace filtered msrs. Fixes: 291f35fb2c1d1 ("KVM: x86: report negative values from wrmsr emulation to userspace") Reported-by: Qian Cai <cai@redhat.com> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20201101115523.115780-1-mlevitsk@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.h')
-rw-r--r--arch/x86/kvm/x86.h8
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 3900ab0c6004..e7ca622a468f 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -376,7 +376,13 @@ int kvm_handle_memory_failure(struct kvm_vcpu *vcpu, int r,
int kvm_handle_invpcid(struct kvm_vcpu *vcpu, unsigned long type, gva_t gva);
bool kvm_msr_allowed(struct kvm_vcpu *vcpu, u32 index, u32 type);
-#define KVM_MSR_RET_INVALID 2
+/*
+ * Internal error codes that are used to indicate that MSR emulation encountered
+ * an error that should result in #GP in the guest, unless userspace
+ * handles it.
+ */
+#define KVM_MSR_RET_INVALID 2 /* in-kernel MSR emulation #GP condition */
+#define KVM_MSR_RET_FILTERED 3 /* #GP due to userspace MSR filter */
#define __cr4_reserved_bits(__cpu_has, __c) \
({ \