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 E03A9606A327 for ; Wed, 28 Oct 2026 15:32:10 +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=0ea9Ux2M; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=Aeg1DChs 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: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:In-Reply-To:References: List-Unsubscribe-Post:List-Owner; bh=ht9WUxyatyt/F/skn5itMNnUaqsNQIudb7pG2aMoxEk=; b=0ea9Ux2MGU9tkO6g3TNNu9G5Ba KXCuS2vpQ7B9HNq2FWbCpDXIBPgzN77UTk/glg0U/fqZFk5noJfXTCuJC6bwdN8vdQAkXsZypNt6b Kh4Qy9VJZ1PauX9RpSs4VYIAO6Czhrl8IWQvUD+ag1RQwek2ZRD4PE1sn+GHm0S/uNyuuziOAIfoW GBY9ggPKjMvtQwA1LACpDUAiKFdkHFrNPoht7zxQ2aj2VK/dwGAIACezLn409BWe3wuYZT5cWpwc/ ogz00VOuLElghmdOpJkfjopzk/DGlkVijkrVWq+u8GoKFfgluZjUPngsC9GHVEG0XUuyMnzk6ooSo r+Yjm6HA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xM5dC-00000007Obi-23G2; Wed, 28 Oct 2026 15:32:02 +0000 Received: from out-160.mta1.migadu.com ([95.215.58.160] helo=mta1.migadu.com) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xM5dA-00000007Oat-0DNb for linux-arm-kernel@lists.infradead.org; Wed, 28 Oct 2026 15:32:01 +0000 X-Envelope-To: linux-arm-kernel@lists.infradead.org DKIM-Signature: a=rsa-sha256; bh=ZTWMSahcNXio61k2+E3NsswZxtgAxnlSsoLAtP0uISQ=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793201517; v=1; x=1793806317; b=Aeg1DChsMb9hcUlrxe+YoPOS2vcNvhxGq711ffbNVJclJcFMFBaLFxVYqvTRCOzTyVzXIQZ/ Kv+JhWrETEzBCGGMkZgPgxjS23mvKp3YD/z/owt+19Ag4qp6bnWbxhG2kPDksUGtJXK0Inv0jPZ s6o3L8d751aRLOzQ2G5mJLus= X-Envelope-To: linux-arm-kernel@lists.infradead.org Received: by smtp.migadu.com with ESMTPS id 1c20b6414d7e255c; Wed, 28 Oct 2026 15:31:57 +0000 X-Mizu-Trace-ID: 1c20b6414d7e255c 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 v3 0/3] KVM: arm64: Fix PMU handling in pKVM Date: Wed, 28 Oct 2026 15:31:49 +0000 Message-ID: <20261028153152.1740044-1-fuad.tabba@linux.dev> X-Mailer: git-send-email 2.47.3 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_083200_307746_8A52C35B X-CRM114-Status: UNSURE ( 8.61 ) X-CRM114-Notice: Please train this message. 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=-13.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_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 Hi folks, Changes since v2 [1]: - Stop the host's counters with PMCR_EL0.E rather than the individual counter enables. (Marc) Two fixes and a hardening patch for PMU handling in pKVM, as one series [2]. The first is Vincent's rework of his HPMN fix. It supersedes his earlier posting [3]. Rather than read nr_event_counters through a different accessor, the host copies the hypervisor's kvm_host_data before it's deprivileged, so host_data_ptr() returns what was set up at init. Otherwise, HPMN is 0 and a non-protected guest's event counters don't count. The second is the non-protected half of Oliver's patch from 2024 [4]. It passes the host's PMU events to the hyp vCPU of a non-protected guest, whose counters otherwise all read 0. The third covers the protected half. It stops the host's counters while a protected guest runs, so the host can't count the guest's cycles and events. Side channels are outside pKVM's threat model, so it carries no Fixes: tag. Based on kvmarm/next (dd0bc00e3e920). Cheers, /fuad [1] https://lore.kernel.org/all/20261028110739.2366566-1-fuad.tabba@linux.dev/ [2] https://lore.kernel.org/all/86bj8kzix4.wl-maz@kernel.org/ [3] https://lore.kernel.org/all/20261023092007.3918848-1-vdonnefort@google.com/ [4] https://lore.kernel.org/all/20240305184840.636212-2-oliver.upton@linux.dev/ Fuad Tabba (1): KVM: arm64: Disable host PMU counters for protected guests Oliver Upton (1): KVM: arm64: Pass the PMU events to the hyp vCPU of non-protected guests Vincent Donnefort (1): KVM: arm64: Synchronise kvm_host_data before host deprivileging arch/arm64/kvm/hyp/nvhe/hyp-main.c | 11 +++++++++++ arch/arm64/kvm/hyp/nvhe/switch.c | 24 ++++++++++++++++++++++++ arch/arm64/kvm/pkvm.c | 6 ++++++ 3 files changed, 41 insertions(+) base-commit: dd0bc00e3e9201fd49b62ff9cc07890c89003afe -- 2.47.3