Received-SPF: pass (google.com: domain of linux-kernel+bounces-13253-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
From: Atish Patra <atishp@rivosinc.com>
To: linux-kernel@vger.kernel.org
Cc: Atish Patra <atishp@rivosinc.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Alexandre Ghiti <alexghiti@rivosinc.com>,
	Andrew Jones <ajones@ventanamicro.com>,
	Anup Patel <anup@brainfault.org>,
	Atish Patra <atishp@atishpatra.org>,
	Conor Dooley <conor.dooley@microchip.com>,
	Guo Ren <guoren@kernel.org>,
	Heiko Stuebner <heiko@sntech.de>,
	kvm-riscv@lists.infradead.org,
	kvm@vger.kernel.org,
	linux-riscv@lists.infradead.org,
	Mark Rutland <mark.rutland@arm.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Will Deacon <will@kernel.org>
Subject: [v2 06/10] RISC-V: KVM: No need to update the counter value during reset
Date: Fri, 29 Dec 2023 13:49:46 -0800
Message-Id: <20231229214950.4061381-7-atishp@rivosinc.com>
In-Reply-To: <20231229214950.4061381-1-atishp@rivosinc.com>
References: <20231229214950.4061381-1-atishp@rivosinc.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

The virtual counter value is updated during pmu_ctr_read. There is no need
to update it in reset case. Otherwise, it will be counted twice which is
incorrect.

Fixes: 0cb74b65d2e5 ("RISC-V: KVM: Implement perf support without sampling")
Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 arch/riscv/kvm/vcpu_pmu.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c
index 86391a5061dd..8c44f26e754d 100644
--- a/arch/riscv/kvm/vcpu_pmu.c
+++ b/arch/riscv/kvm/vcpu_pmu.c
@@ -432,12 +432,9 @@ int kvm_riscv_vcpu_pmu_ctr_stop(struct kvm_vcpu *vcpu, unsigned long ctr_base,
 				sbiret = SBI_ERR_ALREADY_STOPPED;
 			}
 
-			if (flags & SBI_PMU_STOP_FLAG_RESET) {
-				/* Relase the counter if this is a reset request */
-				pmc->counter_val += perf_event_read_value(pmc->perf_event,
-									  &enabled, &running);
+			if (flags & SBI_PMU_STOP_FLAG_RESET)
+				/* Release the counter if this is a reset request */
 				kvm_pmu_release_perf_event(pmc);
-			}
 		} else {
 			sbiret = SBI_ERR_INVALID_PARAM;
 		}
-- 
2.34.1