From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-174.mta0.migadu.com (out-174.mta0.migadu.com [91.218.175.174]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 75B96424666 for ; Thu, 16 Jul 2026 13:24:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.174 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784208286; cv=none; b=TbRjpG/wtHUfixrM0yJfjbAbypeCdkKu4CYmabkAabuAoJ750f0kBBXCuLru5uEy48Nnxp/VAtlgwL1IT58/0b4pcMriJzZ2Y2a+bv0rjx3LRBroSqAHPXfQYZnvlet2UlpLRTiWbZTdKR+iIJCRq6sGE3Tfm+hzeQm6olbuGJ8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784208286; c=relaxed/simple; bh=JvFqrI83C2RHykThmNFrvkcQJ1wzgyexu2ft33c5iF8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Q6uj4JPkqN7qN/iTKCB7OcJ3v6VhqDKZpG16DXYFuyc4MVfeALrWLO91QgrOTuALppsIenVJpvWgSo1YaX/p3NOlQjE3/xrFwAVlK/h7wcoGb6UJC0aLyO6s0ZyCJH5EiS344gLXjh4yzRVYl+3As3w3qzhtV95N+0av+d/hb8w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=peLjuU2E; arc=none smtp.client-ip=91.218.175.174 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) header.d=linux.dev header.i=@linux.dev header.b="peLjuU2E" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1784208280; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SKUFZ1mie4XPvtXG3cHHSaY2hGPjC1MSjIImg1/vHCM=; b=peLjuU2EIwFBDutSbMObnYvGhVbD6oO5w0gUU+UBJ/k5HtPBRdSS2VQqvSZUcoM/qElQaW nca6twKghDlKD9hVCk33+gGWi3IEII6wp9gL7Rcvt37rFucrpb8C8MsudfeYGpAr5MiePY neIScZAm+1YHS4vWylqWPWZN7PGYJK0= From: Fuad Tabba To: stable@vger.kernel.org Cc: Hyunwoo Kim , Marc Zyngier , Greg Kroah-Hartman , Fuad Tabba , Will Deacon Subject: [PATCH 6.18.y] KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU Date: Thu, 16 Jul 2026 14:24:34 +0100 Message-Id: <20260716132434.239763-1-fuad.tabba@linux.dev> In-Reply-To: <2026071615-pastor-showy-ff79@gregkh> References: <2026071615-pastor-showy-ff79@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT From: Hyunwoo Kim flush_hyp_vcpu() copies the host vGIC state into the hyp's private vCPU on every run. The vGIC list register save and restore use used_lrs as their loop bound and expect it to stay within the number of implemented list registers. While this is generally the case, flush_hyp_vcpu() copies vgic_v3 verbatim and does not enforce this, so a value provided by the host is used at EL2 to index vgic_lr[] and access ICH_LR_EL2 (host -> EL2). Fix by clamping used_lrs to the number of implemented list registers after the copy, as the trusted path already does in vgic_flush_lr_state(). The number of implemented list registers is constant after init, so it is replicated once from kvm_vgic_global_state.nr_lr into hyp_gicv3_nr_lr rather than read on every entry. Cc: stable@vger.kernel.org Fixes: be66e67f1750 ("KVM: arm64: Use the pKVM hyp vCPU structure in handle___kvm_vcpu_run()") Signed-off-by: Hyunwoo Kim Reviewed-by: Fuad Tabba Tested-by: Fuad Tabba Link: https://patch.msgid.link/20260606175614.83273-3-imv4bel@gmail.com Signed-off-by: Marc Zyngier (cherry picked from commit 8cc8bbbfab14c22c5551d0dd19b208a44b141c76) [ tabba: adjust context in flush_hyp_vcpu() and kvm_hyp.h ] Signed-off-by: Fuad Tabba --- arch/arm64/include/asm/kvm_hyp.h | 1 + arch/arm64/kvm/arm.c | 2 ++ arch/arm64/kvm/hyp/nvhe/hyp-main.c | 9 +++++++++ 3 files changed, 12 insertions(+) diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h index e6be1f5d0967..8020e91b536d 100644 --- a/arch/arm64/include/asm/kvm_hyp.h +++ b/arch/arm64/include/asm/kvm_hyp.h @@ -146,5 +146,6 @@ extern u64 kvm_nvhe_sym(id_aa64smfr0_el1_sys_val); extern unsigned long kvm_nvhe_sym(__icache_flags); extern unsigned int kvm_nvhe_sym(kvm_arm_vmid_bits); extern unsigned int kvm_nvhe_sym(kvm_host_sve_max_vl); +extern unsigned int kvm_nvhe_sym(hyp_gicv3_nr_lr); #endif /* __ARM64_KVM_HYP_H__ */ diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index e59cb36b5f36..10fc6783cd60 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -2311,6 +2311,8 @@ static int __init init_subsystems(void) switch (err) { case 0: vgic_present = true; + if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) + kvm_nvhe_sym(hyp_gicv3_nr_lr) = kvm_vgic_global_state.nr_lr; break; case -ENODEV: case -ENXIO: diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 29430c031095..edc4508ef2a8 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -22,6 +22,9 @@ DEFINE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params); +/* Number of implemented GICv3 LRs. Used by flush_hyp_vcpu(). */ +unsigned int hyp_gicv3_nr_lr; + void __kvm_hyp_host_forward_smc(struct kvm_cpu_context *host_ctxt); static void __hyp_sve_save_guest(struct kvm_vcpu *vcpu) @@ -136,6 +139,12 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) hyp_vcpu->vcpu.arch.vsesr_el2 = host_vcpu->arch.vsesr_el2; hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3 = host_vcpu->arch.vgic_cpu.vgic_v3; + + /* Bound used_lrs by the number of implemented list registers. */ + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs = + min_t(unsigned int, + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs, + hyp_gicv3_nr_lr); } static void sync_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) -- 2.39.5