diff options
| author | Like Xu <likexu@tencent.com> | 2022-01-25 19:52:23 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-01-26 12:14:58 -0500 |
| commit | 1ffce0924a8c86cf0590c039cd5f5c9375d32e9b (patch) | |
| tree | 2650f7f7266ccc207f34c916bdbb686342941544 | |
| parent | 35fe7cfbab2e81f1afb23fc4212210b1de6d9633 (diff) | |
| download | linux-1ffce0924a8c86cf0590c039cd5f5c9375d32e9b.tar.bz2 | |
KVM: x86/cpuid: Exclude unpermitted xfeatures sizes at KVM_GET_SUPPORTED_CPUID
With the help of xstate_get_guest_group_perm(), KVM can exclude unpermitted
xfeatures in cpuid.0xd.0.eax, in which case the corresponding xfeatures
sizes should also be matched to the permitted xfeatures.
To fix this inconsistency, the permitted_xcr0 and permitted_xss are defined
consistently, which implies 'supported' plus certain permissions for this
task, and it also fixes cpuid.0xd.1.ebx and later leaf-by-leaf queries.
Fixes: 445ecdf79be0 ("kvm: x86: Exclude unpermitted xfeatures at KVM_GET_SUPPORTED_CPUID")
Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20220125115223.33707-1-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 25 |
1 files changed, 13 insertions, 12 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 89d7822a8f5b..8e2704b50e47 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -899,13 +899,14 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) } break; case 0xd: { - u64 guest_perm = xstate_get_guest_group_perm(); + u64 permitted_xcr0 = supported_xcr0 & xstate_get_guest_group_perm(); + u64 permitted_xss = supported_xss; - entry->eax &= supported_xcr0 & guest_perm; - entry->ebx = xstate_required_size(supported_xcr0, false); + entry->eax &= permitted_xcr0; + entry->ebx = xstate_required_size(permitted_xcr0, false); entry->ecx = entry->ebx; - entry->edx &= (supported_xcr0 & guest_perm) >> 32; - if (!supported_xcr0) + entry->edx &= permitted_xcr0 >> 32; + if (!permitted_xcr0) break; entry = do_host_cpuid(array, function, 1); @@ -914,20 +915,20 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) cpuid_entry_override(entry, CPUID_D_1_EAX); if (entry->eax & (F(XSAVES)|F(XSAVEC))) - entry->ebx = xstate_required_size(supported_xcr0 | supported_xss, + entry->ebx = xstate_required_size(permitted_xcr0 | permitted_xss, true); else { - WARN_ON_ONCE(supported_xss != 0); + WARN_ON_ONCE(permitted_xss != 0); entry->ebx = 0; } - entry->ecx &= supported_xss; - entry->edx &= supported_xss >> 32; + entry->ecx &= permitted_xss; + entry->edx &= permitted_xss >> 32; for (i = 2; i < 64; ++i) { bool s_state; - if (supported_xcr0 & BIT_ULL(i)) + if (permitted_xcr0 & BIT_ULL(i)) s_state = false; - else if (supported_xss & BIT_ULL(i)) + else if (permitted_xss & BIT_ULL(i)) s_state = true; else continue; @@ -941,7 +942,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) * invalid sub-leafs. Only valid sub-leafs should * reach this point, and they should have a non-zero * save state size. Furthermore, check whether the - * processor agrees with supported_xcr0/supported_xss + * processor agrees with permitted_xcr0/permitted_xss * on whether this is an XCR0- or IA32_XSS-managed area. */ if (WARN_ON_ONCE(!entry->eax || (entry->ecx & 0x1) != s_state)) { |