On 10/06/2018 20:49, Vitaly Kuznetsov wrote:
> Add support for Hyper-V TLB flush which recently got added to KVM.
>
> Just like regular Hyper-V we announce HV_EX_PROCESSOR_MASKS_RECOMMENDED
> regardless of how many vCPUs we have. Windows is 'smart' and uses less
> expensive non-EX Hypercall whenever possible (when it wants to flush TLB
> for all vCPUs or the maximum vCPU index in the vCPU set requires flushing
> is less than 64).
>
> Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com>
> ---
> linux-headers/linux/kvm.h | 1 +
> target/i386/cpu.c | 1 +
> target/i386/cpu.h | 1 +
> target/i386/hyperv-proto.h | 1 +
> target/i386/kvm.c | 15 ++++++++++++++-
> 5 files changed, 18 insertions(+), 1 deletion(-)
>
> diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
> index cdb148e959..a52a685690 100644
> --- a/linux-headers/linux/kvm.h
> +++ b/linux-headers/linux/kvm.h
> @@ -948,6 +948,7 @@ struct kvm_ppc_resize_hpt {
> #define KVM_CAP_S390_BPB 152
> #define KVM_CAP_GET_MSR_FEATURES 153
> #define KVM_CAP_HYPERV_EVENTFD 154
> +#define KVM_CAP_HYPERV_TLBFLUSH 155
>
> #ifdef KVM_CAP_IRQ_ROUTING
>
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 94260412e2..756cc78808 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -5151,6 +5151,7 @@ static Property x86_cpu_properties[] = {
> DEFINE_PROP_BOOL("hv-stimer", X86CPU, hyperv_stimer, false),
> DEFINE_PROP_BOOL("hv-frequencies", X86CPU, hyperv_frequencies, false),
> DEFINE_PROP_BOOL("hv-reenlightenment", X86CPU, hyperv_reenlightenment,
> false),
> + DEFINE_PROP_BOOL("hv-tlbflush", X86CPU, hyperv_tlbflush, false),
> DEFINE_PROP_BOOL("check", X86CPU, check_cpuid, true),
> DEFINE_PROP_BOOL("enforce", X86CPU, enforce_cpuid, false),
> DEFINE_PROP_BOOL("kvm", X86CPU, expose_kvm, true),
> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
> index 664504610e..738d695331 100644
> --- a/target/i386/cpu.h
> +++ b/target/i386/cpu.h
> @@ -1363,6 +1363,7 @@ struct X86CPU {
> bool hyperv_stimer;
> bool hyperv_frequencies;
> bool hyperv_reenlightenment;
> + bool hyperv_tlbflush;
> bool check_cpuid;
> bool enforce_cpuid;
> bool expose_kvm;
> diff --git a/target/i386/hyperv-proto.h b/target/i386/hyperv-proto.h
> index 93352ebd2a..d6d5a79293 100644
> --- a/target/i386/hyperv-proto.h
> +++ b/target/i386/hyperv-proto.h
> @@ -58,6 +58,7 @@
> #define HV_APIC_ACCESS_RECOMMENDED (1u << 3)
> #define HV_SYSTEM_RESET_RECOMMENDED (1u << 4)
> #define HV_RELAXED_TIMING_RECOMMENDED (1u << 5)
> +#define HV_EX_PROCESSOR_MASKS_RECOMMENDED (1u << 11)
>
> /*
> * Basic virtualized MSRs
> diff --git a/target/i386/kvm.c b/target/i386/kvm.c
> index 44f70733e7..91c8e952c8 100644
> --- a/target/i386/kvm.c
> +++ b/target/i386/kvm.c
> @@ -585,7 +585,8 @@ static bool hyperv_enabled(X86CPU *cpu)
> cpu->hyperv_runtime ||
> cpu->hyperv_synic ||
> cpu->hyperv_stimer ||
> - cpu->hyperv_reenlightenment);
> + cpu->hyperv_reenlightenment ||
> + cpu->hyperv_tlbflush);
> }
>
> static int kvm_arch_set_tsc_khz(CPUState *cs)
> @@ -823,6 +824,18 @@ int kvm_arch_init_vcpu(CPUState *cs)
> if (cpu->hyperv_vapic) {
> c->eax |= HV_APIC_ACCESS_RECOMMENDED;
> }
> + if (cpu->hyperv_tlbflush) {
> + if (kvm_check_extension(cs->kvm_state,
> + KVM_CAP_HYPERV_TLBFLUSH) <= 0) {
> + fprintf(stderr, "Hyper-V TLB flush support "
> + "(requested by 'hv-tlbflush' cpu flag) "
> + " is not supported by kernel\n");
> + return -ENOSYS;
> + }
> + c->eax |= HV_REMOTE_TLB_FLUSH_RECOMMENDED;
> + c->eax |= HV_EX_PROCESSOR_MASKS_RECOMMENDED;
> + }
> +
> c->ebx = cpu->hyperv_spinlock_attempts;
>
> c = &cpuid_data.entries[cpuid_i++];
>
Queued, thanks.
Paolo
