diff options
| -rw-r--r-- | arch/x86/kvm/cpuid.c | 28 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu.h | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 5 |
3 files changed, 32 insertions, 3 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index d1cbb14f8553..1c5583addc90 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -1231,8 +1231,22 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) entry->eax = entry->ebx = entry->ecx = 0; break; case 0x80000008: { + /* + * GuestPhysAddrSize (EAX[23:16]) is intended for software + * use. + * + * KVM's ABI is to report the effective MAXPHYADDR for the + * guest in PhysAddrSize (phys_as), and the maximum + * *addressable* GPA in GuestPhysAddrSize (g_phys_as). + * + * GuestPhysAddrSize is valid if and only if TDP is enabled, + * in which case the max GPA that can be addressed by KVM may + * be less than the max GPA that can be legally generated by + * the guest, e.g. if MAXPHYADDR>48 but the CPU doesn't + * support 5-level TDP. + */ unsigned int virt_as = max((entry->eax >> 8) & 0xff, 48U); - unsigned int phys_as; + unsigned int phys_as, g_phys_as; /* * If TDP (NPT) is disabled use the adjusted host MAXPHYADDR as @@ -1241,15 +1255,23 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) * paging, too. * * If TDP is enabled, use the raw bare metal MAXPHYADDR as - * reductions to the HPAs do not affect GPAs. + * reductions to the HPAs do not affect GPAs. The max + * addressable GPA is the same as the max effective GPA, except + * that it's capped at 48 bits if 5-level TDP isn't supported + * (hardware processes bits 51:48 only when walking the fifth + * level page table). */ if (!tdp_enabled) { phys_as = boot_cpu_data.x86_phys_bits; + g_phys_as = 0; } else { phys_as = entry->eax & 0xff; + g_phys_as = phys_as; + if (kvm_mmu_get_max_tdp_level() < 5) + g_phys_as = min(g_phys_as, 48); } - entry->eax = phys_as | (virt_as << 8); + entry->eax = phys_as | (virt_as << 8) | (g_phys_as << 16); entry->ecx &= ~(GENMASK(31, 16) | GENMASK(11, 8)); entry->edx = 0; cpuid_entry_override(entry, CPUID_8000_0008_EBX); diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h index 60f21bb4c27b..b410a227c601 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -100,6 +100,8 @@ static inline u8 kvm_get_shadow_phys_bits(void) return boot_cpu_data.x86_phys_bits; } +u8 kvm_mmu_get_max_tdp_level(void); + void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 mmio_mask, u64 access_mask); void kvm_mmu_set_me_spte_mask(u64 me_value, u64 me_mask); void kvm_mmu_set_ept_masks(bool has_ad_bits, bool has_exec_only); diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 992e651540e8..db3a26eb7b75 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -5322,6 +5322,11 @@ static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu) return max_tdp_level; } +u8 kvm_mmu_get_max_tdp_level(void) +{ + return tdp_root_level ? tdp_root_level : max_tdp_level; +} + static union kvm_mmu_page_role kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, union kvm_cpu_role cpu_role) |