6.12-stable review patch. If anyone has any objections, please let me know.
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From: Andrew Jones ajones@ventanamicro.com
[ Upstream commit 0611f78f83c93c000029ab01daa28166d03590ed ]
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 Reviewed-by: Anup Patel anup@brainfault.org Link: https://lore.kernel.org/r/20250217084506.18763-10-ajones@ventanamicro.com Signed-off-by: Anup Patel anup@brainfault.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 9c2ab3dfa93aa..74e3a38c6a29e 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; }