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| author | Maciej S. Szmigiero <maciej.szmigiero@oracle.com> | 2022-05-23 18:26:58 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-05-25 21:26:35 +0200 |
| commit | 267b5e7e378afd260004cb37a66a6fcd641e3b53 (patch) | |
| tree | af356193ca979a9a320b24f56d23f1914b8341e1 | |
| parent | dba2b2941ca2ebd5275b3b2c6e72678f98f83a8a (diff) | |
| download | qemu-267b5e7e378afd260004cb37a66a6fcd641e3b53.zip qemu-267b5e7e378afd260004cb37a66a6fcd641e3b53.tar.gz qemu-267b5e7e378afd260004cb37a66a6fcd641e3b53.tar.bz2 | |
target/i386/kvm: Fix disabling MPX on "-cpu host" with MPX-capable host
Since KVM commit 5f76f6f5ff96 ("KVM: nVMX: Do not expose MPX VMX controls when guest MPX disabled")
it is not possible to disable MPX on a "-cpu host" just by adding "-mpx"
there if the host CPU does indeed support MPX.
QEMU will fail to set MSR_IA32_VMX_TRUE_{EXIT,ENTRY}_CTLS MSRs in this case
and so trigger an assertion failure.
Instead, besides "-mpx" one has to explicitly add also
"-vmx-exit-clear-bndcfgs" and "-vmx-entry-load-bndcfgs" to QEMU command
line to make it work, which is a bit convoluted.
Make the MPX-related bits in FEAT_VMX_{EXIT,ENTRY}_CTLS dependent on MPX
being actually enabled so such workarounds are no longer necessary.
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <51aa2125c76363204cc23c27165e778097c33f0b.1653323077.git.maciej.szmigiero@oracle.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | target/i386/cpu.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 35c3475..3856914 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -1356,6 +1356,14 @@ static FeatureDep feature_dependencies[] = { .to = { FEAT_VMX_SECONDARY_CTLS, VMX_SECONDARY_EXEC_ENABLE_INVPCID }, }, { + .from = { FEAT_7_0_EBX, CPUID_7_0_EBX_MPX }, + .to = { FEAT_VMX_EXIT_CTLS, VMX_VM_EXIT_CLEAR_BNDCFGS }, + }, + { + .from = { FEAT_7_0_EBX, CPUID_7_0_EBX_MPX }, + .to = { FEAT_VMX_ENTRY_CTLS, VMX_VM_ENTRY_LOAD_BNDCFGS }, + }, + { .from = { FEAT_7_0_EBX, CPUID_7_0_EBX_RDSEED }, .to = { FEAT_VMX_SECONDARY_CTLS, VMX_SECONDARY_EXEC_RDSEED_EXITING }, }, |