Re: [PATCH] WHPX: vmware cpuid leaf for tsc and apic frequency

[Paolo Bonzini <pbonzini@redhat.com>]

On 31/07/20 00:11, Sunil Muthuswamy wrote:
> Newer versions of WHPX provide the capability to query the tsc
> and apic frequency. Expose these through the vmware cpuid leaf.
> This patch doesnt support setting the tsc frequency; that will
> come as a separate fix.
> 
> Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com>
> ---
>  target/i386/whp-dispatch.h |  3 +-
>  target/i386/whpx-all.c     | 94 ++++++++++++++++++++++++++++++++++----
>  2 files changed, 86 insertions(+), 11 deletions(-)
> 
> diff --git a/target/i386/whp-dispatch.h b/target/i386/whp-dispatch.h
> index e4695c349f..b18aba20ed 100644
> --- a/target/i386/whp-dispatch.h
> +++ b/target/i386/whp-dispatch.h
> @@ -2,10 +2,11 @@
>  #define WHP_DISPATCH_H
>  
>  #include <windows.h>
> -
>  #include <WinHvPlatform.h>
>  #include <WinHvEmulation.h>
>  
> +#define WHV_E_UNKNOWN_CAPABILITY 0x80370300L
> +
>  #define LIST_WINHVPLATFORM_FUNCTIONS(X) \
>    X(HRESULT, WHvGetCapability, (WHV_CAPABILITY_CODE CapabilityCode, VOID* CapabilityBuffer, UINT32 CapabilityBufferSizeInBytes, UINT32* WrittenSizeInBytes)) \
>    X(HRESULT, WHvCreatePartition, (WHV_PARTITION_HANDLE* Partition)) \
> diff --git a/target/i386/whpx-all.c b/target/i386/whpx-all.c
> index c78baac6df..da4c135925 100644
> --- a/target/i386/whpx-all.c
> +++ b/target/i386/whpx-all.c
> @@ -27,6 +27,8 @@
>  #include <WinHvPlatform.h>
>  #include <WinHvEmulation.h>
>  
> +#define HYPERV_APIC_BUS_FREQUENCY      (200000000ULL)
> +
>  struct whpx_state {
>      uint64_t mem_quota;
>      WHV_PARTITION_HANDLE partition;
> @@ -1061,6 +1063,18 @@ static int whpx_vcpu_run(CPUState *cpu)
>              cpu_x86_cpuid(env, cpuid_fn, 0, (UINT32 *)&rax, (UINT32 *)&rbx,
>                  (UINT32 *)&rcx, (UINT32 *)&rdx);
>              switch (cpuid_fn) {
> +            case 0x40000000:
> +                /* Expose the vmware cpu frequency cpuid leaf */
> +                rax = 0x40000010;
> +                rbx = rcx = rdx = 0;
> +                break;
> +
> +            case 0x40000010:
> +                rax = env->tsc_khz;
> +                rbx = env->apic_bus_freq / 1000; /* Hz to KHz */
> +                rcx = rdx = 0;
> +                break;
> +
>              case 0x80000001:
>                  /* Remove any support of OSVW */
>                  rcx &= ~CPUID_EXT3_OSVW;
> @@ -1193,6 +1207,10 @@ int whpx_init_vcpu(CPUState *cpu)
>      struct whpx_state *whpx = &whpx_global;
>      struct whpx_vcpu *vcpu;
>      Error *local_error = NULL;
> +    struct CPUX86State *env = (CPUArchState *)(cpu->env_ptr);
> +    X86CPU *x86_cpu = X86_CPU(cpu);
> +    UINT64 freq = 0;
> +    int ret;
>  
>      /* Add migration blockers for all unsupported features of the
>       * Windows Hypervisor Platform
> @@ -1207,7 +1225,8 @@ int whpx_init_vcpu(CPUState *cpu)
>              error_report_err(local_error);
>              migrate_del_blocker(whpx_migration_blocker);
>              error_free(whpx_migration_blocker);
> -            return -EINVAL;
> +            ret = -EINVAL;
> +            goto error;
>          }
>      }
>  
> @@ -1215,7 +1234,8 @@ int whpx_init_vcpu(CPUState *cpu)
>  
>      if (!vcpu) {
>          error_report("WHPX: Failed to allocte VCPU context.");
> -        return -ENOMEM;
> +        ret = -ENOMEM;
> +        goto error;
>      }
>  
>      hr = whp_dispatch.WHvEmulatorCreateEmulator(
> @@ -1224,8 +1244,8 @@ int whpx_init_vcpu(CPUState *cpu)
>      if (FAILED(hr)) {
>          error_report("WHPX: Failed to setup instruction completion support,"
>                       " hr=%08lx", hr);
> -        g_free(vcpu);
> -        return -EINVAL;
> +        ret = -EINVAL;
> +        goto error;
>      }
>  
>      hr = whp_dispatch.WHvCreateVirtualProcessor(
> @@ -1234,17 +1254,72 @@ int whpx_init_vcpu(CPUState *cpu)
>          error_report("WHPX: Failed to create a virtual processor,"
>                       " hr=%08lx", hr);
>          whp_dispatch.WHvEmulatorDestroyEmulator(vcpu->emulator);
> -        g_free(vcpu);
> -        return -EINVAL;
> +        ret = -EINVAL;
> +        goto error;
>      }
>  
> -    vcpu->interruptable = true;
> +    /*
> +     * vcpu's TSC frequency is either specified by user, or use the value
> +     * provided by Hyper-V if the former is not present. In the latter case, we
> +     * query it from Hyper-V and record in env->tsc_khz, so that vcpu's TSC
> +     * frequency can be migrated later via this field.
> +     */
> +    if (!env->tsc_khz) {
> +        hr = whp_dispatch.WHvGetCapability(
> +            WHvCapabilityCodeProcessorClockFrequency, &freq, sizeof(freq),
> +                NULL);
> +        if (hr != WHV_E_UNKNOWN_CAPABILITY) {
> +            if (FAILED(hr)) {
> +                printf("WHPX: Failed to query tsc frequency, hr=0x%08lx\n", hr);
> +            } else {
> +                env->tsc_khz = freq / 1000; /* Hz to KHz */
> +            }
> +        }
> +    }
>  
> +    env->apic_bus_freq = HYPERV_APIC_BUS_FREQUENCY;
> +    hr = whp_dispatch.WHvGetCapability(
> +        WHvCapabilityCodeInterruptClockFrequency, &freq, sizeof(freq), NULL);
> +    if (hr != WHV_E_UNKNOWN_CAPABILITY) {
> +        if (FAILED(hr)) {
> +            printf("WHPX: Failed to query apic bus frequency hr=0x%08lx\n", hr);
> +        } else {
> +            env->apic_bus_freq = freq;
> +        }
> +    }
> +
> +    /*
> +     * If the vmware cpuid frequency leaf option is set, and we have a valid
> +     * tsc value, trap the corresponding cpuid's.
> +     */
> +    if (x86_cpu->vmware_cpuid_freq && env->tsc_khz) {
> +        UINT32 cpuidExitList[] = {1, 0x80000001, 0x40000000, 0x40000010};
> +
> +        hr = whp_dispatch.WHvSetPartitionProperty(
> +                whpx->partition,
> +                WHvPartitionPropertyCodeCpuidExitList,
> +                cpuidExitList,
> +                RTL_NUMBER_OF(cpuidExitList) * sizeof(UINT32));
> +
> +        if (FAILED(hr)) {
> +            error_report("WHPX: Failed to set partition CpuidExitList hr=%08lx",
> +                        hr);
> +            ret = -EINVAL;
> +            goto error;
> +        }
> +    }
> +
> +    vcpu->interruptable = true;
>      cpu->vcpu_dirty = true;
>      cpu->hax_vcpu = (struct hax_vcpu_state *)vcpu;
>      qemu_add_vm_change_state_handler(whpx_cpu_update_state, cpu->env_ptr);
>  
>      return 0;
> +
> +error:
> +    g_free(vcpu);
> +
> +    return ret;
>  }
>  
>  int whpx_vcpu_exec(CPUState *cpu)
> @@ -1493,6 +1568,7 @@ static int whpx_accel_init(MachineState *ms)
>      WHV_CAPABILITY whpx_cap;
>      UINT32 whpx_cap_size;
>      WHV_PARTITION_PROPERTY prop;
> +    UINT32 cpuidExitList[] = {1, 0x80000001};
>  
>      whpx = &whpx_global;
>  
> @@ -1551,7 +1627,6 @@ static int whpx_accel_init(MachineState *ms)
>          goto error;
>      }
>  
> -    UINT32 cpuidExitList[] = {1, 0x80000001};
>      hr = whp_dispatch.WHvSetPartitionProperty(
>          whpx->partition,
>          WHvPartitionPropertyCodeCpuidExitList,
> @@ -1579,14 +1654,13 @@ static int whpx_accel_init(MachineState *ms)
>      printf("Windows Hypervisor Platform accelerator is operational\n");
>      return 0;
>  
> -  error:
> +error:
>  
>      if (NULL != whpx->partition) {
>          whp_dispatch.WHvDeletePartition(whpx->partition);
>          whpx->partition = NULL;
>      }
>  
> -
>      return ret;
>  }
>  
> 

Queued, thanks.

Paolo