Commit 38b3390e authored by Andrew Jones's avatar Andrew Jones Committed by Anup Patel
Browse files

RISC-V: KVM: Add SBI STA info to vcpu_arch 



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: default avatarAnup Patel <anup@brainfault.org>
Reviewed-by: default avatarAtish Patra <atishp@rivosinc.com>
Signed-off-by: default avatarAndrew Jones <ajones@ventanamicro.com>
Signed-off-by: default avatarAnup Patel <anup@brainfault.org>
parent 2a1f6bf0

arch/riscv/include/asm/kvm_host.h

+7 −0
Original line number Diff line number Diff line
@@ -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__ */

arch/riscv/kvm/vcpu.c

+2 −0
Original line number Diff line number Diff line
@@ -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());

arch/riscv/kvm/vcpu_sbi_sta.c

+10 −0
Original line number Diff line number Diff line
@@ -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)