ANDROID: KVM: arm64: Add protected_shared_mem statistic
When using nVHE in protected mode, protected memory can be shared
between host and a guest. Tracking this value is interesting from a
debug perspective to identify potential leaks.
Keeping the count of memory sharing is easy, each share/unshare will
return to the host where the accounting will take place.
Bug: 278749606
Bug: 222044477
Change-Id: I43dcd258789f79dbfe489e5bf721e606c5e6e022
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 3eead18..ae5e37b 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -1162,6 +1162,7 @@ static inline bool __vcpu_write_sys_reg_to_cpu(u64 val, int reg)
struct kvm_vm_stat {
struct kvm_vm_stat_generic generic;
atomic64_t protected_hyp_mem;
+ atomic64_t protected_shared_mem;
};
struct kvm_vcpu_stat {
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 0b797ed..bff8c12 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -32,6 +32,7 @@
const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
KVM_GENERIC_VM_STATS(),
STATS_DESC_ICOUNTER(VM, protected_hyp_mem),
+ STATS_DESC_ICOUNTER(VM, protected_shared_mem),
};
const struct kvm_stats_header kvm_vm_stats_header = {
diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c
index b0e9975..26e1f55 100644
--- a/arch/arm64/kvm/hypercalls.c
+++ b/arch/arm64/kvm/hypercalls.c
@@ -85,6 +85,8 @@ static bool kvm_smccc_default_allowed(u32 func_id)
case ARM_SMCCC_VERSION_FUNC_ID:
case ARM_SMCCC_ARCH_FEATURES_FUNC_ID:
case ARM_SMCCC_VENDOR_HYP_KVM_MMIO_GUARD_MAP_FUNC_ID:
+ case ARM_SMCCC_VENDOR_HYP_KVM_MEM_SHARE_FUNC_ID:
+ case ARM_SMCCC_VENDOR_HYP_KVM_MEM_UNSHARE_FUNC_ID:
return true;
default:
/* PSCI 0.2 and up is in the 0:0x1f range */
@@ -396,6 +398,16 @@ int kvm_smccc_call_handler(struct kvm_vcpu *vcpu)
pkvm_host_reclaim_page(vcpu->kvm, smccc_get_arg1(vcpu));
val[0] = SMCCC_RET_SUCCESS;
break;
+ case ARM_SMCCC_VENDOR_HYP_KVM_MEM_SHARE_FUNC_ID:
+ case ARM_SMCCC_VENDOR_HYP_KVM_MEM_UNSHARE_FUNC_ID:
+ if (!kvm_vm_is_protected(vcpu->kvm))
+ break;
+ atomic64_add(
+ func_id == ARM_SMCCC_VENDOR_HYP_KVM_MEM_SHARE_FUNC_ID ?
+ PAGE_SIZE : -PAGE_SIZE,
+ &vcpu->kvm->stat.protected_shared_mem);
+ val[0] = SMCCC_RET_SUCCESS;
+ break;
case ARM_SMCCC_TRNG_VERSION:
case ARM_SMCCC_TRNG_FEATURES:
case ARM_SMCCC_TRNG_GET_UUID:
