diff mbox series

[v3,06/13] RISC-V: KVM: Add SBI STA info to vcpu_arch

Message ID 20231217204019.36492-21-ajones@ventanamicro.com (mailing list archive)
State Superseded
Headers show
Series RISC-V: Add steal-time support | expand

Checks

Context Check Description
conchuod/vmtest-fixes-PR fail merge-conflict

Commit Message

Andrew Jones Dec. 17, 2023, 8:40 p.m. UTC 
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.

Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
---
 arch/riscv/include/asm/kvm_host.h |  7 +++++++
 arch/riscv/kvm/vcpu.c             |  2 ++
 arch/riscv/kvm/vcpu_sbi_sta.c     | 10 ++++++++++
 3 files changed, 19 insertions(+)

Comments

Atish Patra Dec. 19, 2023, 1:49 a.m. UTC | #1 
On Sun, Dec 17, 2023 at 12:40 PM Andrew Jones <ajones@ventanamicro.com> wrote:
>
> 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.
>
> Reviewed-by: Anup Patel <anup@brainfault.org>
> Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
> ---
>  arch/riscv/include/asm/kvm_host.h |  7 +++++++
>  arch/riscv/kvm/vcpu.c             |  2 ++
>  arch/riscv/kvm/vcpu_sbi_sta.c     | 10 ++++++++++
>  3 files changed, 19 insertions(+)
>
> diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
> index 230b82c3118d..525cba63e0c5 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) {}
> @@ -373,6 +379,7 @@ bool kvm_riscv_vcpu_has_interrupts(struct kvm_vcpu *vcpu, u64 mask);
>  void kvm_riscv_vcpu_power_off(struct kvm_vcpu *vcpu);
>  void kvm_riscv_vcpu_power_on(struct kvm_vcpu *vcpu);
>
> +void kvm_riscv_vcpu_sbi_sta_reset(struct kvm_vcpu *vcpu);
>  void kvm_riscv_vcpu_record_steal_time(struct kvm_vcpu *vcpu);
>
>  #endif /* __RISCV_KVM_HOST_H__ */
> diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
> index 6995b8b641e4..b5ca9f2e98ac 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));
>
> +       kvm_riscv_vcpu_sbi_sta_reset(vcpu);
> +
>         /* 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..6592d287fc4e 100644
> --- a/arch/riscv/kvm/vcpu_sbi_sta.c
> +++ b/arch/riscv/kvm/vcpu_sbi_sta.c
> @@ -8,8 +8,18 @@
>  #include <asm/kvm_vcpu_sbi.h>
>  #include <asm/sbi.h>
>
> +void kvm_riscv_vcpu_sbi_sta_reset(struct kvm_vcpu *vcpu)
> +{
> +       vcpu->arch.sta.shmem = INVALID_GPA;
> +       vcpu->arch.sta.last_steal = 0;
> +}
> +
>  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
>

Reviewed-by: Atish Patra <atishp@rivosinc.com>
diff mbox series

Patch

diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
index 230b82c3118d..525cba63e0c5 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) {}
@@ -373,6 +379,7 @@  bool kvm_riscv_vcpu_has_interrupts(struct kvm_vcpu *vcpu, u64 mask);
 void kvm_riscv_vcpu_power_off(struct kvm_vcpu *vcpu);
 void kvm_riscv_vcpu_power_on(struct kvm_vcpu *vcpu);
 
+void kvm_riscv_vcpu_sbi_sta_reset(struct kvm_vcpu *vcpu);
 void kvm_riscv_vcpu_record_steal_time(struct kvm_vcpu *vcpu);
 
 #endif /* __RISCV_KVM_HOST_H__ */
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index 6995b8b641e4..b5ca9f2e98ac 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));
 
+	kvm_riscv_vcpu_sbi_sta_reset(vcpu);
+
 	/* 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..6592d287fc4e 100644
--- a/arch/riscv/kvm/vcpu_sbi_sta.c
+++ b/arch/riscv/kvm/vcpu_sbi_sta.c
@@ -8,8 +8,18 @@ 
 #include <asm/kvm_vcpu_sbi.h>
 #include <asm/sbi.h>
 
+void kvm_riscv_vcpu_sbi_sta_reset(struct kvm_vcpu *vcpu)
+{
+	vcpu->arch.sta.shmem = INVALID_GPA;
+	vcpu->arch.sta.last_steal = 0;
+}
+
 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)