diff mbox series

[v4,04/10] RISC-V: KVM: do not EOPNOTSUPP in set KVM_REG_RISCV_TIMER_REG

Message ID 20230803163302.445167-5-dbarboza@ventanamicro.com (mailing list archive)
State Handled Elsewhere
Headers show
Series RISC-V: KVM: change get_reg/set_reg error code | expand

Checks

Context Check Description
conchuod/tree_selection fail Failed to apply to next/pending-fixes, riscv/for-next or riscv/master

Commit Message

Daniel Henrique Barboza Aug. 3, 2023, 4:32 p.m. UTC 
The KVM_REG_RISCV_TIMER_REG can be read via get_one_reg(). But trying to
write anything in this reg via set_one_reg() results in an EOPNOTSUPP.

Change the API to behave like cbom_block_size: instead of always
erroring out with EOPNOTSUPP, allow userspace to write the same value
(riscv_timebase) back, throwing an EINVAL if a different value is
attempted.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 arch/riscv/kvm/vcpu_timer.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/riscv/kvm/vcpu_timer.c b/arch/riscv/kvm/vcpu_timer.c
index 527d269cafff..75486b25ac45 100644
--- a/arch/riscv/kvm/vcpu_timer.c
+++ b/arch/riscv/kvm/vcpu_timer.c
@@ -218,7 +218,8 @@  int kvm_riscv_vcpu_set_reg_timer(struct kvm_vcpu *vcpu,
 
 	switch (reg_num) {
 	case KVM_REG_RISCV_TIMER_REG(frequency):
-		ret = -EOPNOTSUPP;
+		if (reg_val != riscv_timebase)
+			return -EINVAL;
 		break;
 	case KVM_REG_RISCV_TIMER_REG(time):
 		gt->time_delta = reg_val - get_cycles64();