https://bugzilla.kernel.org/show_bug.cgi?id=219618 Bug ID: 219618 Summary: qemu cannot not start with -cpu hypervisor=off parameter Product: Virtualization Version: unspecified Hardware: AMD OS: Linux Status: NEW Severity: normal Priority: P3 Component: kvm Assignee: virtualization_kvm@xxxxxxxxxxxxxxxxxxxx Reporter: athul.krishna.kr@xxxxxxxxxxxxxx Regression: No Device: Asus Zephyrus GA402RJ CPU: Ryzen 7 6800HS Kernel: 6.13.0-rc3-g800f6e23e031 Problem: After kernel 6.12, my qemu windows 11 vm won't start when using '-cpu hypervisor=off'. Commit: 74a0e79df68a8042fb84fd7207e57b70722cf825 is the first bad commit commit 74a0e79df68a8042fb84fd7207e57b70722cf825 Author: Sean Christopherson <seanjc@xxxxxxxxxx> Date: Fri Aug 2 11:19:26 2024 -0700 KVM: SVM: Disallow guest from changing userspace's MSR_AMD64_DE_CFG value Inject a #GP if the guest attempts to change MSR_AMD64_DE_CFG from its *current* value, not if the guest attempts to write a value other than KVM's set of supported bits. As per the comment and the changelog of the original code, the intent is to effectively make MSR_AMD64_DE_CFG read- only for the guest. Opportunistically use a more conventional equality check instead of an exclusive-OR check to detect attempts to change bits. Fixes: d1d93fa90f1a ("KVM: SVM: Add MSR-based feature support for serializing LFENCE") Cc: Tom Lendacky <thomas.lendacky@xxxxxxx> Reviewed-by: Tom Lendacky <thomas.lendacky@xxxxxxx> Link: https://lore.kernel.org/r/20240802181935.292540-2-seanjc@xxxxxxxxxx Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> arch/x86/kvm/svm/svm.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) -- You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.
