/**
* Patches the instructions necessary for making a hypercall to the hypervisor.
* Used by GIM.
*
* @returns VBox status code.
* @param pVM Pointer to the VM.
* @param pvBuf The buffer in the hypercall page(s) to be patched.
* @param cbBuf The size of the buffer.
* @param pcbWritten Where to store the number of bytes patched. This
* is reliably updated only when this function returns
* VINF_SUCCESS.
*/
VMM_INT_DECL(int) VMMPatchHypercall(PVM pVM, void *pvBuf, size_t cbBuf, size_t *pcbWritten)
{
AssertReturn(pvBuf, VERR_INVALID_POINTER);
AssertReturn(pcbWritten, VERR_INVALID_POINTER);
if (ASMIsAmdCpu())
{
uint8_t abHypercall[] = { 0x0F, 0x01, 0xD9 }; /* VMMCALL */
if (RT_LIKELY(cbBuf >= sizeof(abHypercall)))
{
memcpy(pvBuf, abHypercall, sizeof(abHypercall));
*pcbWritten = sizeof(abHypercall);
return VINF_SUCCESS;
}
return VERR_BUFFER_OVERFLOW;
}
else
{
AssertReturn(ASMIsIntelCpu() || ASMIsViaCentaurCpu(), VERR_UNSUPPORTED_CPU);
uint8_t abHypercall[] = { 0x0F, 0x01, 0xC1 }; /* VMCALL */
if (RT_LIKELY(cbBuf >= sizeof(abHypercall)))
{
memcpy(pvBuf, abHypercall, sizeof(abHypercall));
*pcbWritten = sizeof(abHypercall);
return VINF_SUCCESS;
}
return VERR_BUFFER_OVERFLOW;
}
}
/**
* Initializes the KVM GIM provider.
*
* @returns VBox status code.
* @param pVM Pointer to the VM.
* @param uVersion The interface version this VM should use.
*/
VMMR3_INT_DECL(int) gimR3KvmInit(PVM pVM)
{
AssertReturn(pVM, VERR_INVALID_PARAMETER);
AssertReturn(pVM->gim.s.enmProviderId == GIMPROVIDERID_KVM, VERR_INTERNAL_ERROR_5);
int rc;
PGIMKVM pKvm = &pVM->gim.s.u.Kvm;
/*
* Determine interface capabilities based on the version.
*/
if (!pVM->gim.s.u32Version)
{
/* Basic features. */
pKvm->uBaseFeat = 0
| GIM_KVM_BASE_FEAT_CLOCK_OLD
//| GIM_KVM_BASE_FEAT_NOP_IO_DELAY
//| GIM_KVM_BASE_FEAT_MMU_OP
| GIM_KVM_BASE_FEAT_CLOCK
//| GIM_KVM_BASE_FEAT_ASYNC_PF
//| GIM_KVM_BASE_FEAT_STEAL_TIME
//| GIM_KVM_BASE_FEAT_PV_EOI
| GIM_KVM_BASE_FEAT_PV_UNHALT
;
/* Rest of the features are determined in gimR3KvmInitCompleted(). */
}
/*
* Expose HVP (Hypervisor Present) bit to the guest.
*/
CPUMSetGuestCpuIdFeature(pVM, CPUMCPUIDFEATURE_HVP);
/*
* Modify the standard hypervisor leaves for KVM.
*/
CPUMCPUIDLEAF HyperLeaf;
RT_ZERO(HyperLeaf);
HyperLeaf.uLeaf = UINT32_C(0x40000000);
HyperLeaf.uEax = UINT32_C(0x40000001); /* Minimum value for KVM is 0x40000001. */
HyperLeaf.uEbx = 0x4B4D564B; /* 'KVMK' */
HyperLeaf.uEcx = 0x564B4D56; /* 'VMKV' */
HyperLeaf.uEdx = 0x0000004D; /* 'M000' */
rc = CPUMR3CpuIdInsert(pVM, &HyperLeaf);
AssertLogRelRCReturn(rc, rc);
/*
* Add KVM specific leaves.
*/
HyperLeaf.uLeaf = UINT32_C(0x40000001);
HyperLeaf.uEax = pKvm->uBaseFeat;
HyperLeaf.uEbx = 0; /* Reserved */
HyperLeaf.uEcx = 0; /* Reserved */
HyperLeaf.uEdx = 0; /* Reserved */
rc = CPUMR3CpuIdInsert(pVM, &HyperLeaf);
AssertLogRelRCReturn(rc, rc);
/*
* Insert all MSR ranges of KVM.
*/
for (unsigned i = 0; i < RT_ELEMENTS(g_aMsrRanges_Kvm); i++)
{
rc = CPUMR3MsrRangesInsert(pVM, &g_aMsrRanges_Kvm[i]);
AssertLogRelRCReturn(rc, rc);
}
/*
* Setup hypercall and #UD handling.
*/
for (VMCPUID i = 0; i < pVM->cCpus; i++)
VMMHypercallsEnable(&pVM->aCpus[i]);
if (ASMIsAmdCpu())
{
pKvm->fTrapXcptUD = true;
pKvm->uOpCodeNative = OP_VMMCALL;
}
else
{
Assert(ASMIsIntelCpu() || ASMIsViaCentaurCpu());
pKvm->fTrapXcptUD = false;
pKvm->uOpCodeNative = OP_VMCALL;
}
/* We always need to trap VMCALL/VMMCALL hypercall using #UDs for raw-mode VMs. */
if (!HMIsEnabled(pVM))
pKvm->fTrapXcptUD = true;
return VINF_SUCCESS;
}
