[PATCH 2/3] riscv: kvm: Fix vstimecmp update hazard on RV32

From: Naohiko Shimizu
Date: Sat Jan 03 2026 - 04:47:12 EST


Signed-off-by: Naohiko Shimizu <naohiko.shimizu@xxxxxxxxx>
---
arch/riscv/kvm/vcpu_timer.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/kvm/vcpu_timer.c b/arch/riscv/kvm/vcpu_timer.c
index 85a7262115e1..f36247e4c783 100644
--- a/arch/riscv/kvm/vcpu_timer.c
+++ b/arch/riscv/kvm/vcpu_timer.c
@@ -72,8 +72,9 @@ static int kvm_riscv_vcpu_timer_cancel(struct kvm_vcpu_timer *t)
static int kvm_riscv_vcpu_update_vstimecmp(struct kvm_vcpu *vcpu, u64 ncycles)
{
#if defined(CONFIG_32BIT)
- ncsr_write(CSR_VSTIMECMP, ncycles & 0xFFFFFFFF);
+ ncsr_write(CSR_VSTIMECMP, ULONG_MAX);
ncsr_write(CSR_VSTIMECMPH, ncycles >> 32);
+ ncsr_write(CSR_VSTIMECMP, (u32)ncycles);
#else
ncsr_write(CSR_VSTIMECMP, ncycles);
#endif
@@ -307,8 +308,9 @@ void kvm_riscv_vcpu_timer_restore(struct kvm_vcpu *vcpu)
return;

#if defined(CONFIG_32BIT)
- ncsr_write(CSR_VSTIMECMP, (u32)t->next_cycles);
+ ncsr_write(CSR_VSTIMECMP, ULONG_MAX);
ncsr_write(CSR_VSTIMECMPH, (u32)(t->next_cycles >> 32));
+ ncsr_write(CSR_VSTIMECMP, (u32)(t->next_cycles));
#else
ncsr_write(CSR_VSTIMECMP, t->next_cycles);
#endif
--
2.39.5