On Wed, Oct 02, 2013 at 04:06:13PM +0200, Paolo Bonzini wrote: > As soon as the kernel will support the XSAVE extensions in Skylake > processors, we will want both userspace and the hypervisor to run > guests without showing any trace of the new features (because > support for them in the hypervisor will come later). > > This series does exactly this. Patches 1 and 3 ensures that userspace > does not get access to features not supported in the hypervisor. > Patch 2 does the same for the guest. > > The effect of these patches is already visible together with > the corresponding QEMU patches and a command line such as "-cpu > SandyBridge,-avx". Previously, the guest could still enable AVX via > xsetbv, and state would be sent by QEMU during migration. These patches > make sure that disabling AVX will really prevent the guest from using it, > which helps if you have to deal with migration from newer versions of > QEMU and the kernel to older versions. The QEMU patches set up the > guest's 0xd CPUID leaf, which also ensures that the kernel has the > necessary information. > > Paolo > Applied, thanks. > v2->v3: > rename supported_xcr0 field to guest_supported_xcr0 > rename xstate_size field to guest_xstate_size > do not hardcode XSTATE_FPSSE in guest_supported_xcr0 > handle missing 0xd leaf > > Paolo Bonzini (3): > KVM: x86: mask unsupported XSAVE entries from leaf 0Dh index 0 > KVM: x86: prevent setting unsupported XSAVE states > KVM: x86: only copy XSAVE state for the supported features > > arch/x86/include/asm/kvm_host.h | 2 ++ > arch/x86/kvm/cpuid.c | 36 +++++++++++++++++++++++++++++++++++- > arch/x86/kvm/x86.c | 29 ++++++++++++++++++++++------- > arch/x86/kvm/x86.h | 1 + > 4 files changed, 60 insertions(+), 8 deletions(-) > > -- > 1.8.3.1 -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
