| Message ID | 20250217084506.18763-10-ajones@ventanamicro.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | riscv: KVM: Fix a few SBI issues | expand |
On Mon, Feb 17, 2025 at 2:15 PM Andrew Jones <ajones@ventanamicro.com> wrote: > > When an invalid function ID of an SBI extension is used we should > return not-supported, not invalid-param. Also, when we see that at > least one hartid constructed from the base and mask parameters is > invalid, then we should return invalid-param. Finally, rather than > relying on overflowing a left shift to result in zero and then using > that zero in a condition which [correctly] skips sending an IPI (but > loops unnecessarily), explicitly check for overflow and exit the loop > immediately. > > Fixes: 5f862df5585c ("RISC-V: KVM: Add v0.1 replacement SBI extensions defined in v0.2") > Signed-off-by: Andrew Jones <ajones@ventanamicro.com> LGTM. Reviewed-by: Anup Patel <anup@brainfault.org> Regards, Anup > --- > arch/riscv/kvm/vcpu_sbi_replace.c | 13 +++++++++++-- > 1 file changed, 11 insertions(+), 2 deletions(-) > > diff --git a/arch/riscv/kvm/vcpu_sbi_replace.c b/arch/riscv/kvm/vcpu_sbi_replace.c > index 9c2ab3dfa93a..74e3a38c6a29 100644 > --- a/arch/riscv/kvm/vcpu_sbi_replace.c > +++ b/arch/riscv/kvm/vcpu_sbi_replace.c > @@ -51,9 +51,10 @@ static int kvm_sbi_ext_ipi_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > struct kvm_cpu_context *cp = &vcpu->arch.guest_context; > unsigned long hmask = cp->a0; > unsigned long hbase = cp->a1; > + unsigned long hart_bit = 0, sentmask = 0; > > if (cp->a6 != SBI_EXT_IPI_SEND_IPI) { > - retdata->err_val = SBI_ERR_INVALID_PARAM; > + retdata->err_val = SBI_ERR_NOT_SUPPORTED; > return 0; > } > > @@ -62,15 +63,23 @@ static int kvm_sbi_ext_ipi_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > if (hbase != -1UL) { > if (tmp->vcpu_id < hbase) > continue; > - if (!(hmask & (1UL << (tmp->vcpu_id - hbase)))) > + hart_bit = tmp->vcpu_id - hbase; > + if (hart_bit >= __riscv_xlen) > + goto done; > + if (!(hmask & (1UL << hart_bit))) > continue; > } > ret = kvm_riscv_vcpu_set_interrupt(tmp, IRQ_VS_SOFT); > if (ret < 0) > break; > + sentmask |= 1UL << hart_bit; > kvm_riscv_vcpu_pmu_incr_fw(tmp, SBI_PMU_FW_IPI_RCVD); > } > > +done: > + if (hbase != -1UL && (hmask ^ sentmask)) > + retdata->err_val = SBI_ERR_INVALID_PARAM; > + > return ret; > } > > -- > 2.48.1 >
diff --git a/arch/riscv/kvm/vcpu_sbi_replace.c b/arch/riscv/kvm/vcpu_sbi_replace.c index 9c2ab3dfa93a..74e3a38c6a29 100644 --- a/arch/riscv/kvm/vcpu_sbi_replace.c +++ b/arch/riscv/kvm/vcpu_sbi_replace.c @@ -51,9 +51,10 @@ static int kvm_sbi_ext_ipi_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, struct kvm_cpu_context *cp = &vcpu->arch.guest_context; unsigned long hmask = cp->a0; unsigned long hbase = cp->a1; + unsigned long hart_bit = 0, sentmask = 0; if (cp->a6 != SBI_EXT_IPI_SEND_IPI) { - retdata->err_val = SBI_ERR_INVALID_PARAM; + retdata->err_val = SBI_ERR_NOT_SUPPORTED; return 0; } @@ -62,15 +63,23 @@ static int kvm_sbi_ext_ipi_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, if (hbase != -1UL) { if (tmp->vcpu_id < hbase) continue; - if (!(hmask & (1UL << (tmp->vcpu_id - hbase)))) + hart_bit = tmp->vcpu_id - hbase; + if (hart_bit >= __riscv_xlen) + goto done; + if (!(hmask & (1UL << hart_bit))) continue; } ret = kvm_riscv_vcpu_set_interrupt(tmp, IRQ_VS_SOFT); if (ret < 0) break; + sentmask |= 1UL << hart_bit; kvm_riscv_vcpu_pmu_incr_fw(tmp, SBI_PMU_FW_IPI_RCVD); } +done: + if (hbase != -1UL && (hmask ^ sentmask)) + retdata->err_val = SBI_ERR_INVALID_PARAM; + return ret; }
When an invalid function ID of an SBI extension is used we should return not-supported, not invalid-param. Also, when we see that at least one hartid constructed from the base and mask parameters is invalid, then we should return invalid-param. Finally, rather than relying on overflowing a left shift to result in zero and then using that zero in a condition which [correctly] skips sending an IPI (but loops unnecessarily), explicitly check for overflow and exit the loop immediately. Fixes: 5f862df5585c ("RISC-V: KVM: Add v0.1 replacement SBI extensions defined in v0.2") Signed-off-by: Andrew Jones <ajones@ventanamicro.com> --- arch/riscv/kvm/vcpu_sbi_replace.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)