6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Anup Patel apatel@ventanamicro.com
[ Upstream commit 2e7be162996640bbe3b6da694cc064c511b8a5d9 ]
The SBI specification clearly states that SBI HFENCE calls should return SBI_ERR_NOT_SUPPORTED when one of the target hart doesn’t support hypervisor extension (aka nested virtualization in-case of KVM RISC-V).
Fixes: c7fa3c48de86 ("RISC-V: KVM: Treat SBI HFENCE calls as NOPs") Reviewed-by: Atish Patra atishp@rivosinc.com Signed-off-by: Anup Patel apatel@ventanamicro.com Link: https://lore.kernel.org/r/20250605061458.196003-3-apatel@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 | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/riscv/kvm/vcpu_sbi_replace.c b/arch/riscv/kvm/vcpu_sbi_replace.c index 960836e0cac74..36f5386c60db7 100644 --- a/arch/riscv/kvm/vcpu_sbi_replace.c +++ b/arch/riscv/kvm/vcpu_sbi_replace.c @@ -127,9 +127,9 @@ static int kvm_sbi_ext_rfence_handler(struct kvm_vcpu *vcpu, struct kvm_run *run case SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA_ASID: /* * Until nested virtualization is implemented, the - * SBI HFENCE calls should be treated as NOPs + * SBI HFENCE calls should return not supported + * hence fallthrough. */ - break; default: retdata->err_val = SBI_ERR_NOT_SUPPORTED; }