KVM's implementation of SBI STA needs to track the address of each
VCPU's steal-time shared memory region as well as the amount of
stolen time. Add a structure to vcpu_arch to contain this state
and make sure that the address is always set to INVALID_GPA on
vcpu reset. And, of course, ensure KVM won't try to update steal-
time when the shared memory address is invalid.
Signed-off-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
---
arch/riscv/include/asm/kvm_host.h | 6 ++++++
arch/riscv/kvm/vcpu.c | 2 ++
arch/riscv/kvm/vcpu_sbi_sta.c | 4 ++++
3 files changed, 12 insertions(+)
diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
index 230b82c3118d..b10026fb6412 100644
--- a/arch/riscv/include/asm/kvm_host.h
+++ b/arch/riscv/include/asm/kvm_host.h
@@ -263,6 +263,12 @@ struct kvm_vcpu_arch {
/* 'static' configurations which are set only once */
struct kvm_vcpu_config cfg;
+
+ /* SBI steal-time accounting */
+ struct {
+ gpa_t shmem;
+ u64 last_steal;
+ } sta;
};
static inline void kvm_arch_sync_events(struct kvm *kvm) {}
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index 6995b8b641e4..fec4f5fd0fa7 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -83,6 +83,8 @@ static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu)
vcpu->arch.hfence_tail = 0;
memset(vcpu->arch.hfence_queue, 0, sizeof(vcpu->arch.hfence_queue));
+ vcpu->arch.sta.shmem = INVALID_GPA;
+
/* Reset the guest CSRs for hotplug usecase */
if (loaded)
kvm_arch_vcpu_load(vcpu, smp_processor_id());
diff --git a/arch/riscv/kvm/vcpu_sbi_sta.c b/arch/riscv/kvm/vcpu_sbi_sta.c
index e28351c9488b..157c199be0b4 100644
--- a/arch/riscv/kvm/vcpu_sbi_sta.c
+++ b/arch/riscv/kvm/vcpu_sbi_sta.c
@@ -10,6 +10,10 @@
void kvm_riscv_vcpu_record_steal_time(struct kvm_vcpu *vcpu)
{
+ gpa_t shmem = vcpu->arch.sta.shmem;
+
+ if (shmem == INVALID_GPA)
+ return;
}
static int kvm_sbi_sta_steal_time_set_shmem(struct kvm_vcpu *vcpu)
--
2.43.0
