From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 33BB63A5453 for ; Fri, 12 Jun 2026 06:59:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781247581; cv=none; b=LLRc9xzm7vXis6mdO+RFN2ajlD7V2POV1DPjBCzWa+1EgwTiytMXrBbnLkuKHZnVBu4mogDmfd3i8b+qkLD/1EZLk5H2bGwdiu04IsIS+q6C2Qm7hafWw3Sv0UV1sNgdfqiwhTgbXI5fQPVc9rJI6HSA/KFKFWIdssrgz4gHiJU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781247581; c=relaxed/simple; bh=nPvyAKqBIhUojwNk0xa7eh01eFuZtPOkUGrZd/kDP6w=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=fcG9P9cyvo6BFnjUXdwDCxkaro0eHK1W7EIXBZzsCX/JGPo8gss8v1bMA4waYu2oondHuBgE7yIRs1UGVrNTbhwa4xnDQrldZALahES+Q10mgTbjPQHWaHbnE8xmxg1hggCZo1nUiR4/A4b11S4Pvgiut1zR2kWeGLihxmNAc3Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--tabba.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=L+TQd481; arc=none smtp.client-ip=209.85.128.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--tabba.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="L+TQd481" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-490b3ec3f7fso3587845e9.1 for ; Thu, 11 Jun 2026 23:59:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1781247576; x=1781852376; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=xebdFH52a2q7PdzScDZN73wHZPgaOs9QBV3wO9+5R+0=; b=L+TQd481FKPVmomnS395z2OvbEskYiwlPTZolI5YjstZEwIlc/Aiu9Z5sdMXqlunD3 Gf5wluGGdD1ZomgKOqdAb+8QsTcQdeuUJO0vT1QCm3q0p9NTzYwbyEWfEZN5YOkT07Vc cQiD3bi3daybzqTUfLGyIsY2Uy5pM11SHNRHMWOTGJ1L8wyeV+80BOYXE24ywbzRR775 kLdQU45zdY/Gz/f2sCmZuSFJSajYggmrxtCnbe1d3SUZb84e8xQZvDNRfIQHJAOVdFMS nLEqk0aUbgCKpVjS2G5LB5FLLdtnv/ZMHu/tOfLkS6ik1+c20s00gCWjwp2wOuLswBuv c1sg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781247576; x=1781852376; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=xebdFH52a2q7PdzScDZN73wHZPgaOs9QBV3wO9+5R+0=; b=c2BKUPJzCJO4NiNbulBKBi/cBjD571Sv3RrFXjr03Je0mVt9ptlZEbSkPPI3cuAfe5 MANykG/8t5zx5tGibkc6Gb3tpyhNF5g6xjcn6MU6hUVjRGE6qeDCbvAGyNKnvvlreVV/ ocUmIBpbr4IvAcNcsn310SBAyly8PFpUWIOEEUmC8l6DzSpAmlOgT9pp3Z42SHmtdGUO w36ixUcHpHXnJxsorrHxoD+HnLLXw4KxAZLoKyxR9zWccHHSKnK94wy5kh+gMEF0BqHD fvJx/rzk/x8RqfQ1fyck3+oUIyeIiTfRZp6eTmIGxlzAOFbbKQ7DbFqfNNDytGTKWSL2 74Hg== X-Forwarded-Encrypted: i=1; AFNElJ9JMz0JYjE464dBw0IROZS+W/20mBCprWUXf/hti76nS+/6EnbmvCRA1qSyTvcr8atei/JRWSZsgbaB470=@vger.kernel.org X-Gm-Message-State: AOJu0YwAj6cqgShCIvcrUmh4yHwqls3KtxLZCFqD4do2do72q0gf+LbU C0wzoN+zJesibzcOOnvnH4dmKYNODk6auB+jVOfxmz85MpUC8gxID2Cfngbz/AzbWJvHhgNRx+8 vqA== X-Received: from wmby27.prod.google.com ([2002:a05:600c:c05b:b0:483:6e28:c16f]) (user=tabba job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:c4ab:b0:48f:f64c:c2fe with SMTP id 5b1f17b1804b1-490ec4f8090mr18979405e9.22.1781247576386; Thu, 11 Jun 2026 23:59:36 -0700 (PDT) Date: Fri, 12 Jun 2026 07:59:23 +0100 In-Reply-To: <20260612065925.755562-1-tabba@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260612065925.755562-1-tabba@google.com> X-Mailer: git-send-email 2.54.0.1136.gdb2ca164c4-goog Message-ID: <20260612065925.755562-10-tabba@google.com> Subject: [PATCH v1 09/11] KVM: arm64: Minimise EL2's exposure of host VGIC state during world switch From: tabba@google.com To: Marc Zyngier , Oliver Upton Cc: Fuad Tabba , Will Deacon , Catalin Marinas , Quentin Perret , Vincent Donnefort , Sebastian Ene , Per Larsen , Suzuki K Poulose , Zenghui Yu , Joey Gouly , Steffen Eiden , Mark Rutland , Jonathan Cameron , Hyunwoo Kim , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" From: Marc Zyngier The host passes a vgic_v3_cpu_if pointer to the __vgic_v3_save_aprs and __vgic_v3_restore_vmcr_aprs hypercalls, which EL2 dereferences wholesale. That exposes the host's full VGIC emulation state to the hypervisor, against pKVM's isolation goals. Recover the host vCPU from the supplied cpu_if via container_of() and copy only vgic_vmcr and the active priority registers between EL2's hyp-side state and the host vCPU, so EL2 no longer dereferences the host's vgic_v3_cpu_if directly. Signed-off-by: Marc Zyngier Co-developed-by: Fuad Tabba Signed-off-by: Fuad Tabba --- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 67 ++++++++++++++++++++++++++++-- 1 file changed, 63 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 420fb19a6476..2f165b6c7b07 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -7,6 +7,8 @@ #include #include +#include + #include #include #include @@ -220,6 +222,16 @@ static struct kvm_vcpu *__get_host_hyp_vcpus(struct kvm_vcpu *arg, __get_host_hyp_vcpus(__vcpu, hyp_vcpup); \ }) +#define get_host_hyp_vcpus_from_vgic_v3_cpu_if(ctxt, regnr, hyp_vcpup) \ + ({ \ + DECLARE_REG(struct vgic_v3_cpu_if *, cif, ctxt, regnr);\ + struct kvm_vcpu *__vcpu = container_of(cif, \ + struct kvm_vcpu, \ + arch.vgic_cpu.vgic_v3); \ + \ + __get_host_hyp_vcpus(__vcpu, hyp_vcpup); \ + }) + static void handle___kvm_vcpu_run(struct kvm_cpu_context *host_ctxt) { struct pkvm_hyp_vcpu *hyp_vcpu; @@ -489,16 +501,63 @@ static void handle___vgic_v3_init_lrs(struct kvm_cpu_context *host_ctxt) static void handle___vgic_v3_save_aprs(struct kvm_cpu_context *host_ctxt) { - DECLARE_REG(struct vgic_v3_cpu_if *, cpu_if, host_ctxt, 1); + struct pkvm_hyp_vcpu *hyp_vcpu; + struct kvm_vcpu *host_vcpu; - __vgic_v3_save_aprs(kern_hyp_va(cpu_if)); + host_vcpu = get_host_hyp_vcpus_from_vgic_v3_cpu_if(host_ctxt, 1, + &hyp_vcpu); + if (!host_vcpu) + return; + + if (unlikely(hyp_vcpu)) { + struct vgic_v3_cpu_if *hyp_cpu_if, *host_cpu_if; + int i; + + hyp_cpu_if = &hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3; + __vgic_v3_save_aprs(hyp_cpu_if); + + host_cpu_if = &host_vcpu->arch.vgic_cpu.vgic_v3; + host_cpu_if->vgic_vmcr = hyp_cpu_if->vgic_vmcr; + for (i = 0; i < ARRAY_SIZE(host_cpu_if->vgic_ap0r); i++) { + host_cpu_if->vgic_ap0r[i] = hyp_cpu_if->vgic_ap0r[i]; + host_cpu_if->vgic_ap1r[i] = hyp_cpu_if->vgic_ap1r[i]; + } + } else { + __vgic_v3_save_aprs(&host_vcpu->arch.vgic_cpu.vgic_v3); + } } static void handle___vgic_v3_restore_vmcr_aprs(struct kvm_cpu_context *host_ctxt) { - DECLARE_REG(struct vgic_v3_cpu_if *, cpu_if, host_ctxt, 1); + struct pkvm_hyp_vcpu *hyp_vcpu; + struct kvm_vcpu *host_vcpu; - __vgic_v3_restore_vmcr_aprs(kern_hyp_va(cpu_if)); + host_vcpu = get_host_hyp_vcpus_from_vgic_v3_cpu_if(host_ctxt, 1, + &hyp_vcpu); + if (!host_vcpu) + return; + + if (unlikely(hyp_vcpu)) { + struct vgic_v3_cpu_if *hyp_cpu_if, *host_cpu_if; + int i; + + hyp_cpu_if = &hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3; + host_cpu_if = &host_vcpu->arch.vgic_cpu.vgic_v3; + + hyp_cpu_if->vgic_vmcr = host_cpu_if->vgic_vmcr; + /* Should be a one-off */ + hyp_cpu_if->vgic_sre = (ICC_SRE_EL1_DIB | + ICC_SRE_EL1_DFB | + ICC_SRE_EL1_SRE); + for (i = 0; i < ARRAY_SIZE(host_cpu_if->vgic_ap0r); i++) { + hyp_cpu_if->vgic_ap0r[i] = host_cpu_if->vgic_ap0r[i]; + hyp_cpu_if->vgic_ap1r[i] = host_cpu_if->vgic_ap1r[i]; + } + + __vgic_v3_restore_vmcr_aprs(hyp_cpu_if); + } else { + __vgic_v3_restore_vmcr_aprs(&host_vcpu->arch.vgic_cpu.vgic_v3); + } } static void handle___pkvm_init(struct kvm_cpu_context *host_ctxt) -- 2.54.0.1136.gdb2ca164c4-goog