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ANDROID: KVM: arm64: Initialize hypervisor vm state at EL2

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Do not rely on the state of the vm as provided by the host, but
initialize it instead at EL2 to a known good and safe state.

Bug: 357781595
Change-Id: I8e0e9fd7cdf0b5b4d422260be06920d0550d5f91
Signed-off-by: Fuad Tabba <tabba@google.com>
This commit is contained in:
Fuad Tabba
2022-04-27 11:25:01 +00:00
committed by Keir Fraser
parent 1fbada8c2c
commit c2821c8213
1 changed files with 84 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
arch/arm64/kvm/hyp/nvhe/pkvm.c
+84
View File
@@ -6,6 +6,9 @@
#include <linux/kvm_host.h>
#include <linux/mm.h>
#include <asm/kvm_emulate.h>
#include <nvhe/mem_protect.h>
#include <nvhe/memory.h>
#include <nvhe/pkvm.h>
@@ -358,6 +361,65 @@ struct pkvm_hyp_vcpu *pkvm_get_loaded_hyp_vcpu(void)
return __this_cpu_read(loaded_hyp_vcpu);
}
static void pkvm_init_features_from_host(struct pkvm_hyp_vm *hyp_vm, const struct kvm *host_kvm)
{
struct kvm *kvm = &hyp_vm->kvm;
DECLARE_BITMAP(allowed_features, KVM_VCPU_MAX_FEATURES);
/* No restrictions for non-protected VMs. */
if (!kvm_vm_is_protected(kvm)) {
bitmap_copy(kvm->arch.vcpu_features,
host_kvm->arch.vcpu_features,
KVM_VCPU_MAX_FEATURES);
return;
}
bitmap_zero(allowed_features, KVM_VCPU_MAX_FEATURES);
/*
* For protected vms, always allow:
* - CPU starting in poweroff state
* - PSCI v0.2
*/
set_bit(KVM_ARM_VCPU_POWER_OFF, allowed_features);
set_bit(KVM_ARM_VCPU_PSCI_0_2, allowed_features);
/*
* Check if remaining features are allowed:
* - Performance Monitoring
* - Scalable Vectors
* - Pointer Authentication
*/
if (FIELD_GET(ARM64_FEATURE_MASK(ID_AA64DFR0_EL1_PMUVer), PVM_ID_AA64DFR0_ALLOW))
set_bit(KVM_ARM_VCPU_PMU_V3, allowed_features);
if (FIELD_GET(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_SVE), PVM_ID_AA64PFR0_ALLOW))
set_bit(KVM_ARM_VCPU_SVE, allowed_features);
if (FIELD_GET(ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_API), PVM_ID_AA64ISAR1_RESTRICT_UNSIGNED) &&
FIELD_GET(ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_APA), PVM_ID_AA64ISAR1_RESTRICT_UNSIGNED))
set_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, allowed_features);
if (FIELD_GET(ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_GPI), PVM_ID_AA64ISAR1_ALLOW) &&
FIELD_GET(ARM64_FEATURE_MASK(ID_AA64ISAR1_EL1_GPA), PVM_ID_AA64ISAR1_ALLOW))
set_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, allowed_features);
bitmap_and(kvm->arch.vcpu_features, host_kvm->arch.vcpu_features,
allowed_features, KVM_VCPU_MAX_FEATURES);
}
static void pkvm_vcpu_init_ptrauth(struct pkvm_hyp_vcpu *hyp_vcpu)
{
struct kvm_vcpu *vcpu = &hyp_vcpu->vcpu;
if (vcpu_has_feature(vcpu, KVM_ARM_VCPU_PTRAUTH_ADDRESS) ||
vcpu_has_feature(vcpu, KVM_ARM_VCPU_PTRAUTH_GENERIC)) {
kvm_vcpu_enable_ptrauth(vcpu);
} else {
vcpu_clear_flag(&hyp_vcpu->vcpu, GUEST_HAS_PTRAUTH);
}
}
static void unpin_host_vcpu(struct kvm_vcpu *host_vcpu)
{
if (host_vcpu)
@@ -384,8 +446,23 @@ static void init_pkvm_hyp_vm(struct kvm *host_kvm, struct pkvm_hyp_vm *hyp_vm,
hyp_vm->host_kvm = host_kvm;
hyp_vm->kvm.created_vcpus = nr_vcpus;
hyp_vm->kvm.arch.mmu.vtcr = host_mmu.arch.mmu.vtcr;
hyp_vm->kvm.arch.pkvm.enabled = READ_ONCE(host_kvm->arch.pkvm.enabled);
hyp_vm->kvm.arch.mmu.last_vcpu_ran = (int __percpu *)last_ran;
memset(last_ran, -1, pkvm_get_last_ran_size());
pkvm_init_features_from_host(hyp_vm, host_kvm);
}
static int pkvm_vcpu_init_sve(struct pkvm_hyp_vcpu *hyp_vcpu, struct kvm_vcpu *host_vcpu)
{
struct kvm_vcpu *vcpu = &hyp_vcpu->vcpu;
if (!vcpu_has_feature(vcpu, KVM_ARM_VCPU_SVE)) {
vcpu_clear_flag(vcpu, GUEST_HAS_SVE);
vcpu_clear_flag(vcpu, VCPU_SVE_FINALIZED);
return 0;
}
return 0;
}
static int init_pkvm_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu,
@@ -411,8 +488,15 @@ static int init_pkvm_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu,
hyp_vcpu->vcpu.arch.hw_mmu = &hyp_vm->kvm.arch.mmu;
hyp_vcpu->vcpu.arch.cflags = READ_ONCE(host_vcpu->arch.cflags);
hyp_vcpu->vcpu.arch.mp_state.mp_state = KVM_MP_STATE_STOPPED;
ret = pkvm_vcpu_init_sve(hyp_vcpu, host_vcpu);
if (ret)
goto done;
pkvm_vcpu_init_ptrauth(hyp_vcpu);
pkvm_vcpu_init_traps(hyp_vcpu);
kvm_reset_pvm_sys_regs(&hyp_vcpu->vcpu);
done:
if (ret)
unpin_host_vcpu(host_vcpu);