RISC-V: KVM: Preserve firmware counter value across stop/start

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Firmware events accumulate in kvpmu->fw_event[].value while running,
but counter stop only clears fw_event[].started without saving the
value back to pmc->counter_val. A subsequent counter start without
SBI_PMU_START_FLAG_SET_INIT_VALUE reloads the stale counter_val into
fw_event[].value, losing all events counted so far.

Save fw_event[].value into counter_val when actually stopping a
running counter, and remove the now redundant synchronization from
the snapshot path.

Fixes: badc386869 ("RISC-V: KVM: Support firmware events")
Signed-off-by: SeungJu Cheon <suunj1331@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260825083719.643970-2-suunj1331@gmail.com
Signed-off-by: Anup Patel <anup@brainfault.org>

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SeungJu Cheon 2026-08-25 17:37:17 +09:00 • committed by Anup Patel

parent b7749531a9

commit 8b3fd1a8b3

1 changed files with 6 additions and 6 deletions

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arch/riscv/kvm/vcpu_pmu.c

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