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 14468606A31B for ; Tue, 27 Oct 2026 08:12:08 +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=yO6x6Zwt; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=U0BJUmhX 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=gb5sZs9kXKkHxMOBK0QCN7nKSbVD+3tuMPiUXhvbYWs=; b=yO6x6Zwt0AZNgvuEIVHzwfNbUk FWg7+fWH+cUDWP2D84D4HWiL+jgrlC12+sjzCVp7HGG8D/aqXmIECkYgRTN+zlcTZUQSI+gEodInh J9DttPucRQbizjK3Jb4W4pZqetWrTbFoNuzZkFg2LXyr4hnQlUcPRzStEHdTjcnRKEwmULUBqfgUx cJTTz+N0CRJStPy9ozC1g1GnHeZpMAEq55QUZlDw++lUwJEyrISnNMAiEO/xdhpAXfz8b9noMW6RG LD4X6R57ZDF+BuEbqFm2BLgnhXofBaNpz2D0j1y5w9zE7e2epjJG9kQJCQSRACcM0X75rB8h6dh4O 7YqbLTOw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLcHn-0000000402a-20n7; Tue, 27 Oct 2026 08:11:59 +0000 Received: from out-38.mta1.migadu.com ([95.215.58.38] helo=mta1.migadu.com) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xLcHj-0000000400o-2xOe for linux-arm-kernel@lists.infradead.org; Tue, 27 Oct 2026 08:11:57 +0000 X-Envelope-To: linux-arm-kernel@lists.infradead.org DKIM-Signature: a=rsa-sha256; bh=uPm1bCuVoiN/lEjit+HbKmRBz2Yja0dVUN8FPqoeyWI=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793088712; v=1; x=1793693512; b=U0BJUmhX6RzNk2/1qkmWnQdb3QryqZz51xgBbvnMpozZvRbiaxWB2hkdQ53sMVYEDPg7u+Cg YqMPfztZI0Y8rZdq9z+651ka5O8LUIvsiXN3dfQe5V4FBJlC2sv1ty+cL9uBOmba9HluKY/CZ7B MmXHxSp6221CY4ky4tZmTbHE= X-Envelope-To: linux-arm-kernel@lists.infradead.org Received: by smtp.migadu.com with ESMTPS id 45e916e20e21a3dd; Tue, 27 Oct 2026 08:11:52 +0000 X-Mizu-Trace-ID: 45e916e20e21a3dd 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 0/3] KVM: arm64: Fix PMU handling in pKVM Date: Tue, 27 Oct 2026 08:11:44 +0000 Message-ID: <20261027081147.498183-1-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-20261027_011155_963354_FA21C0BF X-CRM114-Status: UNSURE ( 9.57 ) X-CRM114-Notice: Please train this message. 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=-14.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_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, Two fixes and a hardening patch for PMU handling in pKVM, as one series [1]. The first is Vincent's rework of his HPMN fix. It supersedes his earlier posting [2]. Rather than read nr_event_counters through a different accessor, the host now 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 [3]. 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/86bj8kzix4.wl-maz@kernel.org/ [2] https://lore.kernel.org/all/20261023092007.3918848-1-vdonnefort@google.com/ [3] 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/include/asm/kvm_host.h | 1 + arch/arm64/kvm/debug.c | 4 +++- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 11 +++++++++++ arch/arm64/kvm/hyp/nvhe/switch.c | 24 ++++++++++++++++++++++++ arch/arm64/kvm/pkvm.c | 6 ++++++ 5 files changed, 45 insertions(+), 1 deletion(-) base-commit: dd0bc00e3e9201fd49b62ff9cc07890c89003afe -- 2.47.3