From: Jing Liu Date: Wed, 5 Jan 2022 12:35:26 +0000 (-0800) Subject: kvm: x86: Add XCR0 support for Intel AMX X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=86aff7a4799286635efd94dab17b513544703cad;p=linux.git kvm: x86: Add XCR0 support for Intel AMX Two XCR0 bits are defined for AMX to support XSAVE mechanism. Bit 17 is for tilecfg and bit 18 is for tiledata. The value of XCR0[17:18] is always either 00b or 11b. Also, SDM recommends that only 64-bit operating systems enable Intel AMX by setting XCR0[18:17]. 32-bit host kernel never sets the tile bits in vcpu->arch.guest_supported_xcr0. Signed-off-by: Jing Liu Signed-off-by: Kevin Tian Signed-off-by: Yang Zhong Message-Id: <20220105123532.12586-16-yang.zhong@intel.com> Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 2475b64cb7621..993eee6451ea3 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -211,7 +211,7 @@ static struct kvm_user_return_msrs __percpu *user_return_msrs; #define KVM_SUPPORTED_XCR0 (XFEATURE_MASK_FP | XFEATURE_MASK_SSE \ | XFEATURE_MASK_YMM | XFEATURE_MASK_BNDREGS \ | XFEATURE_MASK_BNDCSR | XFEATURE_MASK_AVX512 \ - | XFEATURE_MASK_PKRU) + | XFEATURE_MASK_PKRU | XFEATURE_MASK_XTILE) u64 __read_mostly host_efer; EXPORT_SYMBOL_GPL(host_efer); @@ -1010,6 +1010,11 @@ static int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr) if ((xcr0 & XFEATURE_MASK_AVX512) != XFEATURE_MASK_AVX512) return 1; } + + if ((xcr0 & XFEATURE_MASK_XTILE) && + ((xcr0 & XFEATURE_MASK_XTILE) != XFEATURE_MASK_XTILE)) + return 1; + vcpu->arch.xcr0 = xcr0; if ((xcr0 ^ old_xcr0) & XFEATURE_MASK_EXTEND)