From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f73.google.com (mail-wm1-f73.google.com [209.85.128.73]) (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 AE71835E1B3 for ; Fri, 19 Jun 2026 07:07:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781852851; cv=none; b=ioEAbXFANqHfRcv7mHQuFf1xh/ZLGYZOdr/M5fk1Rpp+FkcsjckHXJWrifeyy/fBxmiSGqoxSoi2Jfq2cmHmN2bIQJxSBPVPwF84kXnjNsqulnzILCpeBBDO3gi5CXAro2xgL/2Q3nV1C3c1COYuViW3MRyA7TvYwoB8pXeFp9Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781852851; c=relaxed/simple; bh=YW3jA9tm3/u2Cm7/0Cqvg0Oho7qgO/I+QS7ISjHRBBU=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=G5FIba+LuF1jpX8R8zFmJUFX3arkBWYw1NqwUnNTssBBrWAgrdt0X9sC5yZ7UWEudB0uMP8lhH2TbX+ck3QfF9Mb2za2oAJ/V+7YE+kJcSni0/i9vtShp0s7YT2xw4xbJpNwcR2p54oo4zsWWeEdO/z5Q1QopJ3Rzz5v1IeGbl0= 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=OB4tgS7a; arc=none smtp.client-ip=209.85.128.73 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="OB4tgS7a" Received: by mail-wm1-f73.google.com with SMTP id 5b1f17b1804b1-49244130073so1216125e9.1 for ; Fri, 19 Jun 2026 00:07:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1781852848; x=1782457648; darn=lists.linux.dev; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=nFTjg/IHL8HMr8nAct3jT4CdzzQIgwwmBvMwQOcvCtw=; b=OB4tgS7aX8xfHab4DNYageNsPLzXiL39uBb1yDx9jIc+UQXTYpn+2TjGkf5hk8Eia5 jgkE+L7I9PJU2D0RzH4KPTA3agi3CYBsIOlk2ETZHqv0M8H7aENcBMei1qxPvJgQLeqk Uoo76Z+LrVmgIPEmxWt3llzqp0cBUAAhw4dLC35Y8V/Fh/CBQATT9OlFP2IiAN9WscsH J7SHk9n8jz9gKyUQLBnkUK+7lmlGUjAv7MzNIW1+lyQZb4KcVfqUYlwL0NiR8HdlQbhJ Yq+NTgv+AVF18q7WWEjc2qZ+8Uj7QU7++MUxXPmzW6shq1I+fT0te5vuiMtxYhob9Qwp oTng== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781852848; x=1782457648; 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=nFTjg/IHL8HMr8nAct3jT4CdzzQIgwwmBvMwQOcvCtw=; b=gKg899e4dQl1cm6bpgQVxy1Yf7YV5mwtpddWJsQfkJ6zU4RqvWEwzJxcOqXCrvokgc mgyL84JvJdXWrAJYs0l0FBDAhh8kpFx5XPsXvDtNp9WGyGWRlq8lOiK52nIojUCxhW7K vP6oaaUAJxoSCX6UlpAysmvF/2B+/7/mxki/7lZuK9pfpY0dRV3lrCkhikg7ot6dSGZB 0o/Sfs44EUHZD+DaqNBLSj2J69AH0Py/y27lkZoRbeZAxu1pLmBmSDwLW9vKhVJDHnCB Ibm2gTVKgTUccZW3LU5M1cFaGMFTMEBZMys/3SlvCUIt/Hiw3PJwXb7mU38biTfDODPq S2VQ== X-Forwarded-Encrypted: i=1; AFNElJ9fUNTNA7eOipXsVjKobcf/dwliYlIBXYdylGZCOR/r7WnjQjPkQIM/AW1RRyLcj3SCC0asti8=@lists.linux.dev X-Gm-Message-State: AOJu0YyxVEeLx5USMTJs0x/5myM39fw+zegyyRq8QuX35ElRWp4FSkqj 9MNTYCQsFXgb3roFfdgpCXRZ1UDDDLYRG0JH5ieZaS44NnIVmdRQ/L4tt/FulJa5UIGp1n19Qoq A1Q== X-Received: from wmbf6.prod.google.com ([2002:a05:600c:5946:b0:492:4336:6b5f]) (user=tabba job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:310e:b0:48f:e3e7:3d39 with SMTP id 5b1f17b1804b1-49242328b63mr18197345e9.11.1781852848101; Fri, 19 Jun 2026 00:07:28 -0700 (PDT) Date: Fri, 19 Jun 2026 08:07:17 +0100 In-Reply-To: <20260619070719.812227-1-tabba@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260619070719.812227-1-tabba@google.com> X-Mailer: git-send-email 2.55.0.rc0.738.g0c8ab3ebcc-goog Message-ID: <20260619070719.812227-7-tabba@google.com> Subject: [PATCH v2 6/8] KVM: arm64: Minimise EL2's exposure of host VGIC state during world switch From: Fuad Tabba To: Marc Zyngier , Oliver Upton , kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Catalin Marinas , Will Deacon , Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , Vincent Donnefort , Quentin Perret , Sebastian Ene , Hyunwoo Kim , Fuad Tabba 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 8923f594c264..f25ee3971528 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 @@ -237,6 +239,16 @@ 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; @@ -506,16 +518,63 @@ 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) -- 2.55.0.rc0.738.g0c8ab3ebcc-goog