From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.13 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793185676; b=uP+kemD0uEn162IZ1Pjto2D2Dv/I2yYi/dpE2XwjkDkdz99qfmJ48juUQB7WR04I0rzB nfzdzexI/K7ONeDElZu2tj450hvJGGQe7Gl3kR9exkpxqSxTZeovNVkSjuBMlalDLJFI4 fJ+nkziGTPE7Z6OG5VheoOqUpkF9HrVlRxhv/mGEv3SHrzKQN/BAYEonPhPAlGDXcbHoD q2wBE64AOs535e5yo6w4t1VDFepJOku3IdSUrtQs/PMDN1KjhzH+Oy5U03mTMoDEspEg8 Jmb7UPXoE1/Ar7c17p0+0iaSUjbNWcpUMhhIjYyVXumASTq9rs4urW0XVzVFvw/p3LQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793185676; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding; bh=tNuGjVpCCpWRRwNm7lQ2uEnHwZpiJtdBe9DMgOWbUgg=; b=YbaYn4IA1W3XfBY6OgYPwiA00RLdeRi4qTo+HlIer1QMAsFFSzhisfjnnNsp/5gwcwXu hdMBQcLIkR1MYZL9EOv3x8QxwYVQSsDpn23XG3aIGy+GWFadayUOf0g3Kr32j2qh2g8if JzOzw0965m952oGFxO53Ee5KUqkpEGe/eTqcOxkYju6qMx0cpzdDs8O1sLnQrMheuXqIj jQccHbu0venQbXl9K0XYz+if3fgOwO+QQTou57ca8XCPOE7YqlLzi349ixHeHWkrlCEJx f9/lUfwrXFRv+J+DtLBQB40Y6o2B4lI2WnblJvlt+zaBxZMuqSfjrza7nXVBxnDgbDQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=rz79ZAkk; arc=none smtp.remote-ip=95.215.58.13 Received: from mta1.migadu.com (out-13.mta1.migadu.com [95.215.58.13]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AF5B9606A31A for ; Wed, 28 Oct 2026 11:07:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org AF5B9606A31A Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=rz79ZAkk X-Envelope-To: linux-kernel@vger.kernel.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-kernel@vger.kernel.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-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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