diff options
author | Paolo Bonzini <pbonzini@redhat.com> | 2023-04-26 15:54:40 -0400 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2023-04-26 15:56:01 -0400 |
commit | c21775ae021f8d28bb1b8ab857b7342e0f8b180d (patch) | |
tree | 2402770141d363c07b1c050078bfff427667c5a8 /arch/x86/kvm/x86.h | |
parent | 48b1893ae38bd6d46a9dcfc7b85c70a143fb8cab (diff) | |
parent | 20aef201dafba6a1ffe9daa145c7f2c525b74aae (diff) |
Merge tag 'kvm-x86-selftests-6.4' of https://github.com/kvm-x86/linux into HEAD
KVM selftests, and an AMX/XCR0 bugfix, for 6.4:
- Don't advertise XTILE_CFG in KVM_GET_SUPPORTED_CPUID if XTILE_DATA is
not being reported due to userspace not opting in via prctl()
- Overhaul the AMX selftests to improve coverage and cleanup the test
- Misc cleanups
Diffstat (limited to 'arch/x86/kvm/x86.h')
-rw-r--r-- | arch/x86/kvm/x86.h | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index fbef05c0bdeb..c544602d07a3 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -3,6 +3,7 @@ #define ARCH_X86_KVM_X86_H #include <linux/kvm_host.h> +#include <asm/fpu/xstate.h> #include <asm/mce.h> #include <asm/pvclock.h> #include "kvm_cache_regs.h" @@ -328,6 +329,34 @@ extern struct kvm_caps kvm_caps; extern bool enable_pmu; +/* + * Get a filtered version of KVM's supported XCR0 that strips out dynamic + * features for which the current process doesn't (yet) have permission to use. + * This is intended to be used only when enumerating support to userspace, + * e.g. in KVM_GET_SUPPORTED_CPUID and KVM_CAP_XSAVE2, it does NOT need to be + * used to check/restrict guest behavior as KVM rejects KVM_SET_CPUID{2} if + * userspace attempts to enable unpermitted features. + */ +static inline u64 kvm_get_filtered_xcr0(void) +{ + u64 permitted_xcr0 = kvm_caps.supported_xcr0; + + BUILD_BUG_ON(XFEATURE_MASK_USER_DYNAMIC != XFEATURE_MASK_XTILE_DATA); + + if (permitted_xcr0 & XFEATURE_MASK_USER_DYNAMIC) { + permitted_xcr0 &= xstate_get_guest_group_perm(); + + /* + * Treat XTILE_CFG as unsupported if the current process isn't + * allowed to use XTILE_DATA, as attempting to set XTILE_CFG in + * XCR0 without setting XTILE_DATA is architecturally illegal. + */ + if (!(permitted_xcr0 & XFEATURE_MASK_XTILE_DATA)) + permitted_xcr0 &= ~XFEATURE_MASK_XTILE_CFG; + } + return permitted_xcr0; +} + static inline bool kvm_mpx_supported(void) { return (kvm_caps.supported_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR)) |