diff options
| -rw-r--r-- | accel/kvm/kvm-all.c | 2 | ||||
| -rw-r--r-- | include/system/kvm.h | 1 | ||||
| -rw-r--r-- | target/i386/kvm/kvm.c | 31 |
3 files changed, 29 insertions, 5 deletions
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index 51526d301b..a31778341c 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -99,6 +99,7 @@ bool kvm_allowed; bool kvm_readonly_mem_allowed; bool kvm_vm_attributes_allowed; bool kvm_msi_use_devid; +bool kvm_pre_fault_memory_supported; static bool kvm_has_guest_debug; static int kvm_sstep_flags; static bool kvm_immediate_exit; @@ -2745,6 +2746,7 @@ static int kvm_init(MachineState *ms) kvm_check_extension(s, KVM_CAP_GUEST_MEMFD) && kvm_check_extension(s, KVM_CAP_USER_MEMORY2) && (kvm_supported_memory_attributes & KVM_MEMORY_ATTRIBUTE_PRIVATE); + kvm_pre_fault_memory_supported = kvm_vm_check_extension(s, KVM_CAP_PRE_FAULT_MEMORY); if (s->kernel_irqchip_split == ON_OFF_AUTO_AUTO) { s->kernel_irqchip_split = mc->default_kernel_irqchip_split ? ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF; diff --git a/include/system/kvm.h b/include/system/kvm.h index 62ec131d4d..7cc60d26f2 100644 --- a/include/system/kvm.h +++ b/include/system/kvm.h @@ -42,6 +42,7 @@ extern bool kvm_gsi_routing_allowed; extern bool kvm_gsi_direct_mapping; extern bool kvm_readonly_mem_allowed; extern bool kvm_msi_use_devid; +extern bool kvm_pre_fault_memory_supported; #define kvm_enabled() (kvm_allowed) /** diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index a6bc089d02..56a6b9b638 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -6018,9 +6018,11 @@ static bool host_supports_vmx(void) * because private/shared page tracking is already provided through other * means, these 2 use-cases should be treated as being mutually-exclusive. */ -static int kvm_handle_hc_map_gpa_range(struct kvm_run *run) +static int kvm_handle_hc_map_gpa_range(X86CPU *cpu, struct kvm_run *run) { + struct kvm_pre_fault_memory mem; uint64_t gpa, size, attributes; + int ret; if (!machine_require_guest_memfd(current_machine)) return -EINVAL; @@ -6031,13 +6033,32 @@ static int kvm_handle_hc_map_gpa_range(struct kvm_run *run) trace_kvm_hc_map_gpa_range(gpa, size, attributes, run->hypercall.flags); - return kvm_convert_memory(gpa, size, attributes & KVM_MAP_GPA_RANGE_ENCRYPTED); + ret = kvm_convert_memory(gpa, size, attributes & KVM_MAP_GPA_RANGE_ENCRYPTED); + if (ret || !kvm_pre_fault_memory_supported) { + return ret; + } + + /* + * Opportunistically pre-fault memory in. Failures are ignored so that any + * errors in faulting in the memory will get captured in KVM page fault + * path when the guest first accesses the page. + */ + memset(&mem, 0, sizeof(mem)); + mem.gpa = gpa; + mem.size = size; + while (mem.size) { + if (kvm_vcpu_ioctl(CPU(cpu), KVM_PRE_FAULT_MEMORY, &mem)) { + break; + } + } + + return 0; } -static int kvm_handle_hypercall(struct kvm_run *run) +static int kvm_handle_hypercall(X86CPU *cpu, struct kvm_run *run) { if (run->hypercall.nr == KVM_HC_MAP_GPA_RANGE) - return kvm_handle_hc_map_gpa_range(run); + return kvm_handle_hc_map_gpa_range(cpu, run); return -EINVAL; } @@ -6137,7 +6158,7 @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run) break; #endif case KVM_EXIT_HYPERCALL: - ret = kvm_handle_hypercall(run); + ret = kvm_handle_hypercall(cpu, run); break; case KVM_EXIT_SYSTEM_EVENT: switch (run->system_event.type) { |