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

[Paolo Bonzini]

On 01/09/20 01:32, Sunil Muthuswamy wrote:
> Can I please get some eyes on this?

Yes, sorry about the bad timing (5.1 freeze + Meson conversion +
parental leave).

Paolo

>> -----Original Message-----
>> From: Sunil Muthuswamy
>> Sent: Thursday, July 30, 2020 3:11 PM
>> To: Paolo Bonzini <pbonzini@redhat.com>; Richard Henderson 
>> <rth@twiddle.net>; Eduardo Habkost <ehabkost@redhat.com>
>> Cc: qemu-devel@nongnu.org; Stefan Weil <sw@weilnetz.de>
>> Subject: [PATCH] WHPX: vmware cpuid leaf for tsc and apic frequency
>>
>> 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;
>>  }
>>
>> --
>> 2.25.1
>