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 01B1B606A31C for ; Wed, 28 Oct 2026 11:08:08 +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=kY8XeTpv; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=rz79ZAkk 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=tNuGjVpCCpWRRwNm7lQ2uEnHwZpiJtdBe9DMgOWbUgg=; b=kY8XeTpv44wnX4 vWVeIZACYVpgUx1WVr1Pphvz6X3NRGc19KSuv34gBtDCDW4bKR7q3ZLfqN78PxhbeEHqxsJazWu8o NtHkUQWefkYdFB0rJGTBQ/RbgDhCST6I/fON1FKPoNdwpQf0+nKP4AhoXl4yJbiNl5y27vzFFUDQl jA9qGzVgyZkiAwXRDqqSISLmj5RsTL3tsuNvIsat26P4scUq+75ExkAbdVMSHP2VP3DpBQjt2LRZP 9kWKHLOwvellnXjHxDhhjpxIl1yuL3t4jw90p1qOY/VTR+pOpMoxgnfTZDVnTmX86DPHLQ4aW4PEL czG8mE5HfTr9S1WO5b1w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xM1Vh-00000006pR0-3gwD; Wed, 28 Oct 2026 11:08:01 +0000 Received: from out-206.mta0.migadu.com ([2001:41d0:1004:224b::ce] helo=mta0.migadu.com) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xM1Vc-00000006pOO-0fa8 for linux-arm-kernel@lists.infradead.org; Wed, 28 Oct 2026 11:07:57 +0000 X-Envelope-To: linux-arm-kernel@lists.infradead.org DKIM-Signature: a=rsa-sha256; bh=jRMgEeT/ywsGUFgWQfUZIBCXSXNOChhJpeoxPBa3hhY=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793185673; v=1; x=1793790473; b=rz79ZAkkMbgk9B/hhr/yUdNzCFX4ogETGJH4cJw6do7vaQxu2wtJnBEuOFPrqlRxc2VRAQsr or7kdl4DISmotSL4+CilDOfFUYMoc50dm/i9GiEt73pg8STuvGGrWje4B2+crrpvN0RypLnoCTU mPi4QfbYcoI0BSQVS/2slAPA= X-Envelope-To: linux-arm-kernel@lists.infradead.org Received: by smtp.migadu.com with ESMTPS id 1e1179175c352474; Wed, 28 Oct 2026 11:07:53 +0000 X-Mizu-Trace-ID: 1e1179175c352474 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 v2 2/3] KVM: arm64: Pass the PMU events to the hyp vCPU of non-protected guests Date: Wed, 28 Oct 2026 11:07:38 +0000 Message-ID: <20261028110739.2366566-3-fuad.tabba@linux.dev> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261028110739.2366566-1-fuad.tabba@linux.dev> References: <20261028110739.2366566-1-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-20261028_040756_358584_5962952E X-CRM114-Status: GOOD ( 10.71 ) X-Spam-Score: -2.1 (--) 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=-18.9 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] Tested-by: Vincent Donnefort Reviewed-by: Vincent Donnefort 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