From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C68C9606A31A for ; Tue, 27 Oct 2026 08:12:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=25ufVAT+; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=bH9hg+ds DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Unsubscribe-Post: List-Owner; bh=eYU7nRUviv0PRMWv8pLk4R1PsyRqoA4jjfpx6F91JbE=; b=25ufVAT+Ye9bHU /F1voNwb3700JGHBq9NFH4fpfNa59Ne1vM7GOe0b/G8E/WtKsbqqPf7Buf6Hdjr9upPTM/RuxXZ3I rZxM4TvGmvYYx7a8oTaumUjgeX1WP5gaxFwPPQOHzK8puL2GEvBangl5vGlD0847XIs8dIhznIAqK Q7w9pYmDlu5xDjFZ8Ih6c824Z8pER1uc5fF8mRDCO6dRFzDTAqV3iium7SUcDJso+FDESdAu5SE9l eiNM7bBm5aT2vvMiUM+YCex+qdNuTHNr7sGcxYhXiOKi+t71L+Khfr7QxXC84+YkHLL3rMmLeEOsQ 8cdMuzhp1lQviw0VMF/g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLcHx-0000000406Y-2Ro3; Tue, 27 Oct 2026 08:12:09 +0000 Received: from out-55.mta1.migadu.com ([95.215.58.55] helo=mta1.migadu.com) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLcHm-0000000401i-0Z6c for linux-arm-kernel@lists.infradead.org; Tue, 27 Oct 2026 08:11:59 +0000 X-Envelope-To: linux-arm-kernel@lists.infradead.org DKIM-Signature: a=rsa-sha256; bh=5fNaLh6y2LRSzbC19B0rdBidBP/uTWp/P3MFJPydJ4g=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793088716; v=1; x=1793693516; b=bH9hg+dsFfFLMaoyqNOIZXbMcYS9djHUYeYqmmJ/WFwBCRFCCRLz4m8r8LgHqSHjNUHaLV8a bsBwKoTFMNiPK1U1cvRtSxpz5w7bNnl/q9xr3MYdZameHhnxOiutmE45XQZtkhy5xvMPkc1zhS0 ozDLZLrbBGNWuGu9P2PhjXjA= X-Envelope-To: linux-arm-kernel@lists.infradead.org Received: by smtp.migadu.com with ESMTPS id de9eea40cfde8985; Tue, 27 Oct 2026 08:11:56 +0000 X-Mizu-Trace-ID: de9eea40cfde8985 X-Migadu-Flow: FLOW_OUT From: Fuad Tabba To: Marc Zyngier , Oliver Upton , kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org Cc: Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon , Mark Rutland , Vincent Donnefort , kernel-team@android.com, linux-kernel@vger.kernel.org, Oculytic , Fuad Tabba Subject: [PATCH 2/3] KVM: arm64: Pass the PMU events to the hyp vCPU of non-protected guests Date: Tue, 27 Oct 2026 08:11:46 +0000 Message-ID: <20261027081147.498183-3-fuad.tabba@linux.dev> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261027081147.498183-1-fuad.tabba@linux.dev> References: <20261027081147.498183-1-fuad.tabba@linux.dev> X-Archived-By: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261027_011158_348998_9204E060 X-CRM114-Status: GOOD ( 10.89 ) X-Spam-Score: -2.8 (--) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-19.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 From: Oliver Upton Before every run, the host records in vcpu->arch.pmu.events which perf counters to disable and enable around guest entry, and __pmu_switch_to_guest() applies them at EL2. Since commit be66e67f1750 ("KVM: arm64: Use the pKVM hyp vCPU structure in handle___kvm_vcpu_run()"), protected mode runs the hyp vCPU instead, and flush_hyp_vcpu() never copies the events into it. So the counters backing a non-protected guest's PMU are never enabled, and every counter the guest reads stays at 0, the cycle counter included. The host's counters that exclude guests keep counting the guest as well. Copy the events into the hyp vCPU of a non-protected guest on every run. The events only exist with CONFIG_HW_PERF_EVENTS, so the copy is built under it. Like mdcr_el2, they're host-controlled and never reach a protected guest. Fixes: be66e67f1750 ("KVM: arm64: Use the pKVM hyp vCPU structure in handle___kvm_vcpu_run()") Link: https://lore.kernel.org/all/20240305184840.636212-2-oliver.upton@linux.dev/ Signed-off-by: Oliver Upton [Fuad: non-protected copy only, tested on the hyp vCPU, under CONFIG_HW_PERF_EVENTS, new message] Co-developed-by: Fuad Tabba Signed-off-by: Fuad Tabba --- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index d715aa942577e..28a292deecb64 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -690,6 +690,16 @@ static void sync_debug_state(struct pkvm_hyp_vcpu *hyp_vcpu) host_vcpu->arch.external_debug_state = hyp_vcpu->vcpu.arch.external_debug_state; } +#ifdef CONFIG_HW_PERF_EVENTS +static void flush_pmu_state(struct pkvm_hyp_vcpu *hyp_vcpu) +{ + if (!pkvm_hyp_vcpu_is_protected(hyp_vcpu)) + hyp_vcpu->vcpu.arch.pmu.events = hyp_vcpu->host_vcpu->arch.pmu.events; +} +#else +static void flush_pmu_state(struct pkvm_hyp_vcpu *hyp_vcpu) {} +#endif + static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) { struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu; @@ -698,6 +708,7 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) fpsimd_sve_flush(); flush_debug_state(hyp_vcpu); + flush_pmu_state(hyp_vcpu); /* * If we deal with a non-protected guest and the state is potentially -- 2.47.3