From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 CD6FD27C861; Tue, 8 Apr 2025 12:57:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744117058; cv=none; b=duunwl5NcIkWuPuh+EsU7L7O+BN82nx0B0lwnrnJcxqLQ7B4iNYbko/hRZS7DRpl5XR2lwLYf6mszGtuMr9xMYFiMXcezRtUOpI672A625h1yqudzAZkbkVu4ib0+CaCXPZoLKn0wtgZNuM9dXk2fJaBiDgaFZ6qx6wepwt5fTA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744117058; c=relaxed/simple; bh=ehD7LCrxnboVZEt41lihvG4QqEuXtAS6n3sRmyY/80M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=h1xykPIatPDPy8z9+UH2RqYmqS/e306BjtCkvBhByP/tcIe9Gg9I7T8+LBPte3RuHRDxtBeVTis3XRlJHUZW4K7iuhuwWH1kxf/rcQGBl0L5LhOsAnGlupb2yumRgfU/UuPsEscFW681MykXMEw+S2yu4jJirGhW9VNZmtqMagw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=GC5nnC1t; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="GC5nnC1t" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 57DC1C4CEE5; Tue, 8 Apr 2025 12:57:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1744117058; bh=ehD7LCrxnboVZEt41lihvG4QqEuXtAS6n3sRmyY/80M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GC5nnC1tN6P32BNrabe0N/FVBw94NM42ENcGAfCuwpFrZEQCkAEnrzQXZY1MuUiem vu2Kkry/3TsknsPr1jQHfycFMxPifqNQEi27ZDCqKWvT+uhLvrDUEyluZvfzJVlSbb hpAjcnD8MXuxYU4XdtWp4RRfeTpK7lZNHh67swZA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Paolo Bonzini , Pankaj Gupta Subject: [PATCH 6.12 369/423] KVM: x86: block KVM_CAP_SYNC_REGS if guest state is protected Date: Tue, 8 Apr 2025 12:51:35 +0200 Message-ID: <20250408104854.461110808@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250408104845.675475678@linuxfoundation.org> References: <20250408104845.675475678@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Bonzini commit 74c1807f6c4feddb3c3cb1056c54531d4adbaea6 upstream. KVM_CAP_SYNC_REGS does not make sense for VMs with protected guest state, since the register values cannot actually be written. Return 0 when using the VM-level KVM_CHECK_EXTENSION ioctl, and accordingly return -EINVAL from KVM_RUN if the valid/dirty fields are nonzero. However, on exit from KVM_RUN userspace could have placed a nonzero value into kvm_run->kvm_valid_regs, so check guest_state_protected again and skip store_regs() in that case. Cc: stable@vger.kernel.org Fixes: 517987e3fb19 ("KVM: x86: add fields to struct kvm_arch for CoCo features") Signed-off-by: Paolo Bonzini Message-ID: <20250306202923.646075-1-pbonzini@redhat.com> Reviewed-by: Pankaj Gupta Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/x86.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4590,6 +4590,11 @@ static bool kvm_is_vm_type_supported(uns return type < 32 && (kvm_caps.supported_vm_types & BIT(type)); } +static inline u32 kvm_sync_valid_fields(struct kvm *kvm) +{ + return kvm && kvm->arch.has_protected_state ? 0 : KVM_SYNC_X86_VALID_FIELDS; +} + int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) { int r = 0; @@ -4698,7 +4703,7 @@ int kvm_vm_ioctl_check_extension(struct break; #endif case KVM_CAP_SYNC_REGS: - r = KVM_SYNC_X86_VALID_FIELDS; + r = kvm_sync_valid_fields(kvm); break; case KVM_CAP_ADJUST_CLOCK: r = KVM_CLOCK_VALID_FLAGS; @@ -11470,6 +11475,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_v { struct kvm_queued_exception *ex = &vcpu->arch.exception; struct kvm_run *kvm_run = vcpu->run; + u32 sync_valid_fields; int r; r = kvm_mmu_post_init_vm(vcpu->kvm); @@ -11515,8 +11521,9 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_v goto out; } - if ((kvm_run->kvm_valid_regs & ~KVM_SYNC_X86_VALID_FIELDS) || - (kvm_run->kvm_dirty_regs & ~KVM_SYNC_X86_VALID_FIELDS)) { + sync_valid_fields = kvm_sync_valid_fields(vcpu->kvm); + if ((kvm_run->kvm_valid_regs & ~sync_valid_fields) || + (kvm_run->kvm_dirty_regs & ~sync_valid_fields)) { r = -EINVAL; goto out; } @@ -11574,7 +11581,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_v out: kvm_put_guest_fpu(vcpu); - if (kvm_run->kvm_valid_regs) + if (kvm_run->kvm_valid_regs && likely(!vcpu->arch.guest_state_protected)) store_regs(vcpu); post_kvm_run_save(vcpu); kvm_vcpu_srcu_read_unlock(vcpu);