| Message ID | 20230201231250.3806412-5-atishp@rivosinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM perf support | expand |
On Wed, Feb 01, 2023 at 03:12:40PM -0800, Atish Patra wrote: > Currently the probe function just checks if an SBI extension is > registered or not. However, the extension may not want to advertise > itself depending on some other condition. > An additional extension specific probe function will allow > extensions to decide if they want to be advertised to the caller or > not. Any extension that does not require additional dependency checks > can avoid implementing this function. > > Reviewed-by: Anup Patel <anup@brainfault.org> > Signed-off-by: Atish Patra <atishp@rivosinc.com> > --- > arch/riscv/include/asm/kvm_vcpu_sbi.h | 3 +++ > arch/riscv/kvm/vcpu_sbi_base.c | 13 +++++++++++-- > 2 files changed, 14 insertions(+), 2 deletions(-) > > diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h > index f79478a..45ba341 100644 > --- a/arch/riscv/include/asm/kvm_vcpu_sbi.h > +++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h > @@ -29,6 +29,9 @@ struct kvm_vcpu_sbi_extension { > int (*handler)(struct kvm_vcpu *vcpu, struct kvm_run *run, > unsigned long *out_val, struct kvm_cpu_trap *utrap, > bool *exit); > + > + /* Extension specific probe function */ > + unsigned long (*probe)(struct kvm_vcpu *vcpu); > }; > > void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run); > diff --git a/arch/riscv/kvm/vcpu_sbi_base.c b/arch/riscv/kvm/vcpu_sbi_base.c > index 5d65c63..846d518 100644 > --- a/arch/riscv/kvm/vcpu_sbi_base.c > +++ b/arch/riscv/kvm/vcpu_sbi_base.c > @@ -19,6 +19,7 @@ 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; > + const struct kvm_vcpu_sbi_extension *sbi_ext; > > switch (cp->a6) { > case SBI_EXT_BASE_GET_SPEC_VERSION: > @@ -43,8 +44,16 @@ static int kvm_sbi_ext_base_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > */ > kvm_riscv_vcpu_sbi_forward(vcpu, run); > *exit = true; > - } else > - *out_val = kvm_vcpu_sbi_find_ext(cp->a0) ? 1 : 0; > + } else { > + sbi_ext = kvm_vcpu_sbi_find_ext(cp->a0); > + if (sbi_ext) { > + if (sbi_ext->probe) > + *out_val = sbi_ext->probe(vcpu); > + else > + *out_val = 1; > + } else > + *out_val = 0; Conor points out elsewhere that we need {} on both arms if one arm needs it. We actually don't need {} on either arm, though, or even the if, if we rewrite as *out_val = sbi_ext && sbi_ext->probe ? sbi_ext->probe(vcpu) : !!sbi_ext; Thanks, drew > + } > break; > case SBI_EXT_BASE_GET_MVENDORID: > *out_val = vcpu->arch.mvendorid; > -- > 2.25.1 >
On Thu, Feb 02, 2023 at 04:14:35PM +0100, Andrew Jones wrote: > On Wed, Feb 01, 2023 at 03:12:40PM -0800, Atish Patra wrote: > > Currently the probe function just checks if an SBI extension is > > registered or not. However, the extension may not want to advertise > > itself depending on some other condition. > > An additional extension specific probe function will allow > > extensions to decide if they want to be advertised to the caller or > > not. Any extension that does not require additional dependency checks > > can avoid implementing this function. > > > > Reviewed-by: Anup Patel <anup@brainfault.org> > > Signed-off-by: Atish Patra <atishp@rivosinc.com> > > --- > > arch/riscv/include/asm/kvm_vcpu_sbi.h | 3 +++ > > arch/riscv/kvm/vcpu_sbi_base.c | 13 +++++++++++-- > > 2 files changed, 14 insertions(+), 2 deletions(-) > > > > diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h > > index f79478a..45ba341 100644 > > --- a/arch/riscv/include/asm/kvm_vcpu_sbi.h > > +++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h > > @@ -29,6 +29,9 @@ struct kvm_vcpu_sbi_extension { > > int (*handler)(struct kvm_vcpu *vcpu, struct kvm_run *run, > > unsigned long *out_val, struct kvm_cpu_trap *utrap, > > bool *exit); > > + > > + /* Extension specific probe function */ > > + unsigned long (*probe)(struct kvm_vcpu *vcpu); > > }; > > > > void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run); > > diff --git a/arch/riscv/kvm/vcpu_sbi_base.c b/arch/riscv/kvm/vcpu_sbi_base.c > > index 5d65c63..846d518 100644 > > --- a/arch/riscv/kvm/vcpu_sbi_base.c > > +++ b/arch/riscv/kvm/vcpu_sbi_base.c > > @@ -19,6 +19,7 @@ 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; > > + const struct kvm_vcpu_sbi_extension *sbi_ext; > > > > switch (cp->a6) { > > case SBI_EXT_BASE_GET_SPEC_VERSION: > > @@ -43,8 +44,16 @@ static int kvm_sbi_ext_base_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > > */ > > kvm_riscv_vcpu_sbi_forward(vcpu, run); > > *exit = true; > > - } else > > - *out_val = kvm_vcpu_sbi_find_ext(cp->a0) ? 1 : 0; > > + } else { > > + sbi_ext = kvm_vcpu_sbi_find_ext(cp->a0); > > + if (sbi_ext) { > > + if (sbi_ext->probe) > > + *out_val = sbi_ext->probe(vcpu); > > + else > > + *out_val = 1; > > + } else > > + *out_val = 0; > > Conor points out elsewhere that we need {} on both arms if one arm needs > it. We actually don't need {} on either arm, though, or even the if, if > we rewrite as > > *out_val = sbi_ext && sbi_ext->probe ? sbi_ext->probe(vcpu) : !!sbi_ext; I sent too soon, I meant to add In any case, Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Thanks, drew > > Thanks, > drew > > > + } > > break; > > case SBI_EXT_BASE_GET_MVENDORID: > > *out_val = vcpu->arch.mvendorid; > > -- > > 2.25.1 > >
diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h index f79478a..45ba341 100644 --- a/arch/riscv/include/asm/kvm_vcpu_sbi.h +++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h @@ -29,6 +29,9 @@ struct kvm_vcpu_sbi_extension { int (*handler)(struct kvm_vcpu *vcpu, struct kvm_run *run, unsigned long *out_val, struct kvm_cpu_trap *utrap, bool *exit); + + /* Extension specific probe function */ + unsigned long (*probe)(struct kvm_vcpu *vcpu); }; void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run); diff --git a/arch/riscv/kvm/vcpu_sbi_base.c b/arch/riscv/kvm/vcpu_sbi_base.c index 5d65c63..846d518 100644 --- a/arch/riscv/kvm/vcpu_sbi_base.c +++ b/arch/riscv/kvm/vcpu_sbi_base.c @@ -19,6 +19,7 @@ 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; + const struct kvm_vcpu_sbi_extension *sbi_ext; switch (cp->a6) { case SBI_EXT_BASE_GET_SPEC_VERSION: @@ -43,8 +44,16 @@ static int kvm_sbi_ext_base_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, */ kvm_riscv_vcpu_sbi_forward(vcpu, run); *exit = true; - } else - *out_val = kvm_vcpu_sbi_find_ext(cp->a0) ? 1 : 0; + } else { + sbi_ext = kvm_vcpu_sbi_find_ext(cp->a0); + if (sbi_ext) { + if (sbi_ext->probe) + *out_val = sbi_ext->probe(vcpu); + else + *out_val = 1; + } else + *out_val = 0; + } break; case SBI_EXT_BASE_GET_MVENDORID: *out_val = vcpu->arch.mvendorid;