| Message ID | 20230227101332.636203-4-pbonzini@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | target/i386: Add new CPU model SapphireRapids and new fast string op leaves | expand |
On 2/27/2023 6:13 PM, Paolo Bonzini wrote: > These are just a flag that documents the performance characteristic of > an instruction; it needs no hypervisor support. So include them even > if KVM does not show them. In particular, FZRM/FSRS/FSRC have only > been added very recently, but they are available on Sapphire Rapids > processors. > > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > target/i386/kvm/kvm.c | 17 ++++++++++++++++- > 1 file changed, 16 insertions(+), 1 deletion(-) > > diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c > index 587030199192..fe66a4953d41 100644 > --- a/target/i386/kvm/kvm.c > +++ b/target/i386/kvm/kvm.c > @@ -352,7 +352,7 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, > { > struct kvm_cpuid2 *cpuid; > uint32_t ret = 0; > - uint32_t cpuid_1_edx; > + uint32_t cpuid_1_edx, unused; > uint64_t bitmask; > > cpuid = get_supported_cpuid(s); > @@ -399,10 +399,20 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, > } else if (function == 6 && reg == R_EAX) { > ret |= CPUID_6_EAX_ARAT; /* safe to allow because of emulated APIC */ > } else if (function == 7 && index == 0 && reg == R_EBX) { > + /* Not new instructions, just an optimization. */ > + uint32_t ebx; > + host_cpuid(1, 0, &unused, &ebx, &unused, &unused); ^ It should be leaf 7, not 1. > + ret |= ebx & CPUID_7_0_EBX_ERMS; > + > if (host_tsx_broken()) { > ret &= ~(CPUID_7_0_EBX_RTM | CPUID_7_0_EBX_HLE); > } > } else if (function == 7 && index == 0 && reg == R_EDX) { > + /* Not new instructions, just an optimization. */ > + uint32_t edx; > + host_cpuid(1, 0, &unused, &unused, &unused, &edx); Ditto. > + ret |= edx & CPUID_7_0_EDX_FSRM; > + > /* > * Linux v4.17-v4.20 incorrectly return ARCH_CAPABILITIES on SVM hosts. > * We can detect the bug by checking if MSR_IA32_ARCH_CAPABILITIES is > @@ -411,6 +421,11 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, > if (!has_msr_arch_capabs) { > ret &= ~CPUID_7_0_EDX_ARCH_CAPABILITIES; > } > + } else if (function == 7 && index == 1 && reg == R_EAX) { > + /* Not new instructions, just an optimization. */ > + uint32_t eax; > + host_cpuid(1, 0, &eax, &unused, &unused, &unused); Ditto. After them fixed, Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> > + ret |= eax & (CPUID_7_1_EAX_FZRM | CPUID_7_1_EAX_FSRS | CPUID_7_1_EAX_FSRC); > } else if (function == 0xd && index == 0 && > (reg == R_EAX || reg == R_EDX)) { > /*
On 2/27/23 00:13, Paolo Bonzini wrote: > These are just a flag that documents the performance characteristic of > an instruction; it needs no hypervisor support. So include them even > if KVM does not show them. In particular, FZRM/FSRS/FSRC have only > been added very recently, but they are available on Sapphire Rapids > processors. > > Signed-off-by: Paolo Bonzini<pbonzini@redhat.com> > --- > target/i386/kvm/kvm.c | 17 ++++++++++++++++- > 1 file changed, 16 insertions(+), 1 deletion(-) Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index 587030199192..fe66a4953d41 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -352,7 +352,7 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, { struct kvm_cpuid2 *cpuid; uint32_t ret = 0; - uint32_t cpuid_1_edx; + uint32_t cpuid_1_edx, unused; uint64_t bitmask; cpuid = get_supported_cpuid(s); @@ -399,10 +399,20 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, } else if (function == 6 && reg == R_EAX) { ret |= CPUID_6_EAX_ARAT; /* safe to allow because of emulated APIC */ } else if (function == 7 && index == 0 && reg == R_EBX) { + /* Not new instructions, just an optimization. */ + uint32_t ebx; + host_cpuid(1, 0, &unused, &ebx, &unused, &unused); + ret |= ebx & CPUID_7_0_EBX_ERMS; + if (host_tsx_broken()) { ret &= ~(CPUID_7_0_EBX_RTM | CPUID_7_0_EBX_HLE); } } else if (function == 7 && index == 0 && reg == R_EDX) { + /* Not new instructions, just an optimization. */ + uint32_t edx; + host_cpuid(1, 0, &unused, &unused, &unused, &edx); + ret |= edx & CPUID_7_0_EDX_FSRM; + /* * Linux v4.17-v4.20 incorrectly return ARCH_CAPABILITIES on SVM hosts. * We can detect the bug by checking if MSR_IA32_ARCH_CAPABILITIES is @@ -411,6 +421,11 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, if (!has_msr_arch_capabs) { ret &= ~CPUID_7_0_EDX_ARCH_CAPABILITIES; } + } else if (function == 7 && index == 1 && reg == R_EAX) { + /* Not new instructions, just an optimization. */ + uint32_t eax; + host_cpuid(1, 0, &eax, &unused, &unused, &unused); + ret |= eax & (CPUID_7_1_EAX_FZRM | CPUID_7_1_EAX_FSRS | CPUID_7_1_EAX_FSRC); } else if (function == 0xd && index == 0 && (reg == R_EAX || reg == R_EDX)) { /*
These are just a flag that documents the performance characteristic of an instruction; it needs no hypervisor support. So include them even if KVM does not show them. In particular, FZRM/FSRS/FSRC have only been added very recently, but they are available on Sapphire Rapids processors. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- target/i386/kvm/kvm.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-)