From e08e833616f7eefebdacfd1d743d80ff3c3b2585 Mon Sep 17 00:00:00 2001 From: Radim Krčmář Date: Thu, 4 Dec 2014 18:30:41 +0100 Subject: KVM: cpuid: recompute CPUID 0xD.0:EBX,ECX MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We reused host EBX and ECX, but KVM might not support all features; emulated XSAVE size should be smaller. EBX depends on unknown XCR0, so we default to ECX. SDM CPUID (EAX = 0DH, ECX = 0): EBX Bits 31-00: Maximum size (bytes, from the beginning of the XSAVE/XRSTOR save area) required by enabled features in XCR0. May be different than ECX if some features at the end of the XSAVE save area are not enabled. ECX Bit 31-00: Maximum size (bytes, from the beginning of the XSAVE/XRSTOR save area) of the XSAVE/XRSTOR save area required by all supported features in the processor, i.e all the valid bit fields in XCR0. Signed-off-by: Radim Krčmář Tested-by: Wanpeng Li Signed-off-by: Paolo Bonzini --- arch/x86/kvm/cpuid.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 644bfe828ce1..8a80737ee6e6 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -464,6 +464,8 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, u64 supported = kvm_supported_xcr0(); entry->eax &= supported; + entry->ebx = xstate_required_size(supported, false); + entry->ecx = entry->ebx; entry->edx &= supported >> 32; entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; if (!supported) -- cgit v1.2.3-59-g8ed1b