| Message ID | 1448336037-6035-3-git-send-email-haozhong.zhang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Nov 24, 2015 at 11:33:56AM +0800, Haozhong Zhang wrote: > Following changes are made to the TSC rate setting code in > kvm_arch_init_vcpu(): > * The code is moved to a new function kvm_arch_set_tsc_khz(). > * If kvm_arch_set_tsc_khz() fails, i.e. following two conditions are > both satisfied: > * KVM does not support the TSC scaling or it fails to set vcpu's > TSC rate by KVM_SET_TSC_KHZ, > * the TSC rate to be set is different than the value currently used > by KVM, > then kvm_arch_init_vcpu() will fail. Prevously, > * the lack of TSC scaling never failed kvm_arch_init_vcpu(), > * the failure of KVM_SET_TSC_KHZ failed kvm_arch_init_vcpu() > unconditionally, even though the TSC rate to be set is identical > to the value currently used by KVM. > > Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Reviewed-by: Eduardo Habkost <ehabkost@redhat.com> > --- > target-i386/kvm.c | 40 +++++++++++++++++++++++++++++++++------- > 1 file changed, 33 insertions(+), 7 deletions(-) > > diff --git a/target-i386/kvm.c b/target-i386/kvm.c > index a0fe9d4..1e811ee 100644 > --- a/target-i386/kvm.c > +++ b/target-i386/kvm.c > @@ -524,6 +524,36 @@ static bool hyperv_enabled(X86CPU *cpu) > cpu->hyperv_runtime); > } > > +static int kvm_arch_set_tsc_khz(CPUState *cs) > +{ > + X86CPU *cpu = X86_CPU(cs); > + CPUX86State *env = &cpu->env; > + int r; > + > + if (!env->tsc_khz) { > + return 0; > + } > + > + r = kvm_check_extension(cs->kvm_state, KVM_CAP_TSC_CONTROL) ? > + kvm_vcpu_ioctl(cs, KVM_SET_TSC_KHZ, env->tsc_khz) : > + -ENOTSUP; > + if (r < 0) { > + /* When KVM_SET_TSC_KHZ fails, it's an error only if the current > + * TSC frequency doesn't match the one we want. > + */ > + int cur_freq = kvm_check_extension(cs->kvm_state, KVM_CAP_GET_TSC_KHZ) ? > + kvm_vcpu_ioctl(cs, KVM_GET_TSC_KHZ) : > + -ENOTSUP; > + if (cur_freq <= 0 || cur_freq != env->tsc_khz) { > + error_report("warning: TSC frequency mismatch between " > + "VM and host, and TSC scaling unavailable"); > + return r; > + } > + } > + > + return 0; > +} > + > static Error *invtsc_mig_blocker; > > #define KVM_MAX_CPUID_ENTRIES 100 > @@ -823,13 +853,9 @@ int kvm_arch_init_vcpu(CPUState *cs) > return r; > } > > - r = kvm_check_extension(cs->kvm_state, KVM_CAP_TSC_CONTROL); > - if (r && env->tsc_khz) { > - r = kvm_vcpu_ioctl(cs, KVM_SET_TSC_KHZ, env->tsc_khz); > - if (r < 0) { > - fprintf(stderr, "KVM_SET_TSC_KHZ failed\n"); > - return r; > - } > + r = kvm_arch_set_tsc_khz(cs); > + if (r < 0) { > + return r; > } > > /* vcpu's TSC frequency is either specified by user, or following > -- > 2.4.8 >
diff --git a/target-i386/kvm.c b/target-i386/kvm.c index a0fe9d4..1e811ee 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -524,6 +524,36 @@ static bool hyperv_enabled(X86CPU *cpu) cpu->hyperv_runtime); } +static int kvm_arch_set_tsc_khz(CPUState *cs) +{ + X86CPU *cpu = X86_CPU(cs); + CPUX86State *env = &cpu->env; + int r; + + if (!env->tsc_khz) { + return 0; + } + + r = kvm_check_extension(cs->kvm_state, KVM_CAP_TSC_CONTROL) ? + kvm_vcpu_ioctl(cs, KVM_SET_TSC_KHZ, env->tsc_khz) : + -ENOTSUP; + if (r < 0) { + /* When KVM_SET_TSC_KHZ fails, it's an error only if the current + * TSC frequency doesn't match the one we want. + */ + int cur_freq = kvm_check_extension(cs->kvm_state, KVM_CAP_GET_TSC_KHZ) ? + kvm_vcpu_ioctl(cs, KVM_GET_TSC_KHZ) : + -ENOTSUP; + if (cur_freq <= 0 || cur_freq != env->tsc_khz) { + error_report("warning: TSC frequency mismatch between " + "VM and host, and TSC scaling unavailable"); + return r; + } + } + + return 0; +} + static Error *invtsc_mig_blocker; #define KVM_MAX_CPUID_ENTRIES 100 @@ -823,13 +853,9 @@ int kvm_arch_init_vcpu(CPUState *cs) return r; } - r = kvm_check_extension(cs->kvm_state, KVM_CAP_TSC_CONTROL); - if (r && env->tsc_khz) { - r = kvm_vcpu_ioctl(cs, KVM_SET_TSC_KHZ, env->tsc_khz); - if (r < 0) { - fprintf(stderr, "KVM_SET_TSC_KHZ failed\n"); - return r; - } + r = kvm_arch_set_tsc_khz(cs); + if (r < 0) { + return r; } /* vcpu's TSC frequency is either specified by user, or following
Following changes are made to the TSC rate setting code in kvm_arch_init_vcpu(): * The code is moved to a new function kvm_arch_set_tsc_khz(). * If kvm_arch_set_tsc_khz() fails, i.e. following two conditions are both satisfied: * KVM does not support the TSC scaling or it fails to set vcpu's TSC rate by KVM_SET_TSC_KHZ, * the TSC rate to be set is different than the value currently used by KVM, then kvm_arch_init_vcpu() will fail. Prevously, * the lack of TSC scaling never failed kvm_arch_init_vcpu(), * the failure of KVM_SET_TSC_KHZ failed kvm_arch_init_vcpu() unconditionally, even though the TSC rate to be set is identical to the value currently used by KVM. Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> --- target-i386/kvm.c | 40 +++++++++++++++++++++++++++++++++------- 1 file changed, 33 insertions(+), 7 deletions(-)