RISC-V: KVM: Save mvendorid, marchid, and mimpid when creating VCPU

We should save VCPU mvendorid, marchid, and mimpid at the time
of creating VCPU so that we don't have to do host SBI call every
time Guest/VM ask for these details.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
index 91c74b09a970955956aab6d6f7805cd6cb387d8d..93f43a3e7886538d882c12accf04c9738c3b1985 100644 (file)
--- a/arch/riscv/include/asm/kvm_host.h
+++ b/arch/riscv/include/asm/kvm_host.h
@@ -165,6 +165,11 @@ struct kvm_vcpu_arch {
        /* ISA feature bits (similar to MISA) */
        DECLARE_BITMAP(isa, RISCV_ISA_EXT_MAX);
 
+       /* Vendor, Arch, and Implementation details */
+       unsigned long mvendorid;
+       unsigned long marchid;
+       unsigned long mimpid;
+
        /* SSCRATCH, STVEC, and SCOUNTEREN of Host */
        unsigned long host_sscratch;
        unsigned long host_stvec;

diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index 68c86f632d37074cc3d50bc115df7af588a59dfe..312a8a92686775172fa558eb64837e18d9ae5fcd 100644 (file)
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -21,6 +21,7 @@
 #include <asm/csr.h>
 #include <asm/cacheflush.h>
 #include <asm/hwcap.h>
+#include <asm/sbi.h>
 
 const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
        KVM_GENERIC_VCPU_STATS(),
@@ -171,6 +172,11 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
                        set_bit(host_isa, vcpu->arch.isa);
        }
 
+       /* Setup vendor, arch, and implementation details */
+       vcpu->arch.mvendorid = sbi_get_mvendorid();
+       vcpu->arch.marchid = sbi_get_marchid();
+       vcpu->arch.mimpid = sbi_get_mimpid();
+
        /* Setup VCPU hfence queue */
        spin_lock_init(&vcpu->arch.hfence_lock);
 

diff --git a/arch/riscv/kvm/vcpu_sbi_base.c b/arch/riscv/kvm/vcpu_sbi_base.c
index 0c806f61c629dcbb06ac3ceff6197552a98447d9..5d65c634d30127dff64438b8145770158b0fb65d 100644 (file)
--- a/arch/riscv/kvm/vcpu_sbi_base.c
+++ b/arch/riscv/kvm/vcpu_sbi_base.c
@@ -19,7 +19,6 @@ static int kvm_sbi_ext_base_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
 {
        int ret = 0;
        struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
-       struct sbiret ecall_ret;
 
        switch (cp->a6) {
        case SBI_EXT_BASE_GET_SPEC_VERSION:
@@ -48,13 +47,13 @@ static int kvm_sbi_ext_base_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
                        *out_val = kvm_vcpu_sbi_find_ext(cp->a0) ? 1 : 0;
                break;
        case SBI_EXT_BASE_GET_MVENDORID:
+               *out_val = vcpu->arch.mvendorid;
+               break;
        case SBI_EXT_BASE_GET_MARCHID:
+               *out_val = vcpu->arch.marchid;
+               break;
        case SBI_EXT_BASE_GET_MIMPID:
-               ecall_ret = sbi_ecall(SBI_EXT_BASE, cp->a6, 0, 0, 0, 0, 0, 0);
-               if (!ecall_ret.error)
-                       *out_val = ecall_ret.value;
-               /*TODO: We are unnecessarily converting the error twice */
-               ret = sbi_err_map_linux_errno(ecall_ret.error);
+               *out_val = vcpu->arch.mimpid;
                break;
        default:
                ret = -EOPNOTSUPP;