On Wed, Mar 23, 2022 at 12:43:15 +0100, Paolo Bonzini wrote: > Some AMD processors expose the PKRU extended save state even if they do not > have > the related PKU feature in CPUID. Worse, when they do they report a size of > 64, whereas the expected size of the PKRU extended save state is 8, therefore > the esa->size == eax assertion does not hold. > > The state is already ignored by KVM_GET_SUPPORTED_CPUID because it > was not enabled in the host XCR0. However, QEMU kvm_cpu_xsave_init() > runs before QEMU invokes arch_prctl() to enable dynamically-enabled > save states such as XTILEDATA, and KVM_GET_SUPPORTED_CPUID hides save > states that have yet to be enabled. Therefore, kvm_cpu_xsave_init() > needs to consult the host CPUID instead of KVM_GET_SUPPORTED_CPUID, > and dies with an assertion failure. > > When setting up the ExtSaveArea array to match the host, ignore features that > KVM does not report as supported. This will cause QEMU to skip the incorrect > CPUID leaf instead of tripping the assertion. > > Reported-by: Daniel P. Berrangé <berra...@redhat.com> > Analyzed-by: Yang Zhong <yang.zh...@intel.com> > Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> > --- > target/i386/cpu.c | 4 ++-- > target/i386/cpu.h | 2 ++ > target/i386/kvm/kvm-cpu.c | 19 ++++++++++++------- > 3 files changed, 16 insertions(+), 9 deletions(-)
Tested-by: Peter Krempa <pkre...@redhat.com> With this patch it no longer abort()s on my Ryzen 3900X