From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) (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 2E5397E101 for ; Tue, 23 Apr 2024 15:06:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713884810; cv=none; b=hzHHSn7E12EI4hCtLs4Cpr5NWsgV3RGNwtIdyzmMrjZ9yAz7MjNGzmkb3g7XNGriIIEPU4B6qFRHsP7ot8AHV+bjOycEz0Sg6y6J0FV/e2FBkZ2QWm55FDZeUe0RvKWoU/EVOrMqduOPt9JcSfPbfpOmakizHXOUHXrbv3/DFcQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713884810; c=relaxed/simple; bh=LtTsLZmEyQ38RkEpaI2WcInnKGr7V6SLBF5trKpLcMY=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=IkUoX1SnjqLz76PrBfWQUDyFLwwhYPnIgjELzWr2BwxqDqyesaHiMVcQq+MkrHsl5bjdD6FBl5KY+NP5C62m1RyO2Hf/6rRrT9NfInJfVzI81D5U7VajDjYUyfSMfMTwsmO62dhZH2qLW4u9b+bOKlIXlk66YpUunYjOWaDi6Ug= 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=b/oIswJd; arc=none smtp.client-ip=209.85.219.201 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="b/oIswJd" Received: by mail-yb1-f201.google.com with SMTP id 3f1490d57ef6-dcc0bcf9256so9138065276.3 for ; Tue, 23 Apr 2024 08:06:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1713884808; x=1714489608; 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=93tIZsbDQ7aTB1Ag//lp+a36KMN6Q5Vbahl04yV5u4M=; b=b/oIswJdhz/IiQejoU3x6UvgxgM5jyRf8QgcLcPeVDjt0FP9+Ci+QQIvQZ33jiapjV GZgz7mjzokRSt2jIrSxBIGIUw+LmIUwobLnApXAi7j6nRUSeqJHar0lReWqilHM5hEa2 3rD24p1+kfQ6juLw/kInbOj3gDhOf9qDGtnTUI3LY8fWee7vSYCYNg+7NOLFU47/KCtN AnC4VdKNSgiC+o4s/vk7oeQ2CetnIVKYD35nQg/FM3hbVZCSDjcmnTOsrnGNuVi+fwUv vvvHgL2cJD0lzwzULMWagGkwqizYZxF8zvlMc1Dx2rX/9lOCcCbiUjB6XkLQeHLo9AFg EuSQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1713884808; x=1714489608; 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=93tIZsbDQ7aTB1Ag//lp+a36KMN6Q5Vbahl04yV5u4M=; b=oc3c0yBeYBQqG2yY5E3yTt9Qk+CTif5dffHCaqfkPkk1pVV1z3P7BPmkZoGL6VBaaf 7X7n86SWkjDUPkyJI7/z73F108FxpwHFyZGzBiDcihkLhw2AFInEVEOqsJJbcW1HpNac Tvkw0Ih+P3LmIRW7HEZa8nESH6LrdJscKrIQmvJ4dGeyJHYX9FyGNy2doKDuO7VU+BtU krXC2Z4C+EfVXgYGGpSkXac4LnnG9Psh+Jm8AmnWEk9zOn6s1m7awCBT3zZsHyAslqOa aSXUDavUA8YpdbjI46tg7uGm0HgRddoehoWkSDouSW/c6OEbtuUbc7mnxYdYM4QEwnpb LxUA== X-Gm-Message-State: AOJu0Yz6uT35/alnDWH2y5wqEju9/jvlB7w5/mcMbXsSYy0dWsmFYzv0 FZOKK/eHdgkC5EsEs/SLNc1QkiTGn3N9lAohfTIlI+2uFJkguj3tbbjU68YkvrhjALfp5DuKw94 7VqUP+C06QrBCT16FSIT7e5czJPnIOYpDxDpP4pKZxvMa9jITIOGM5b6PwmAElYmRW0flQbM9wT XwE1eOViEUhzKrKSBt9oj8bH/POfQ= X-Google-Smtp-Source: AGHT+IF3BGfAImGTRx2K3Bx7MtlcUeZG4nt+aXIobBscyZGiLwK6ZllinOOTUyjDlHLTIiYdB6z+AzwJlA== X-Received: from fuad.c.googlers.com ([fda3:e722:ac3:cc00:28:9cb1:c0a8:1613]) (user=tabba job=sendgmr) by 2002:a05:6902:725:b0:dbe:30cd:8fcb with SMTP id l5-20020a056902072500b00dbe30cd8fcbmr1031574ybt.0.1713884807336; Tue, 23 Apr 2024 08:06:47 -0700 (PDT) Date: Tue, 23 Apr 2024 16:05:37 +0100 In-Reply-To: <20240423150538.2103045-1-tabba@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240423150538.2103045-1-tabba@google.com> X-Mailer: git-send-email 2.44.0.769.g3c40516874-goog Message-ID: <20240423150538.2103045-30-tabba@google.com> Subject: [PATCH v4 29/30] KVM: arm64: Restrict supported capabilities for protected VMs From: Fuad Tabba To: kvmarm@lists.linux.dev Cc: maz@kernel.org, will@kernel.org, qperret@google.com, tabba@google.com, seanjc@google.com, alexandru.elisei@arm.com, catalin.marinas@arm.com, philmd@linaro.org, james.morse@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, mark.rutland@arm.com, broonie@kernel.org, joey.gouly@arm.com, rananta@google.com, smostafa@google.com Content-Type: text/plain; charset="UTF-8" For practical reasons as well as security related ones, not all capabilities are supported for protected VMs in pKVM. Add a function that restricts the capabilities for protected VMs. This behaves as an allow-list to ensure that future capabilities are checked for compatibility and security before being allowed for protected VMs. Signed-off-by: Fuad Tabba --- arch/arm64/kvm/arm.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 647c81ebdb1b..cdda89378c63 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -70,6 +70,31 @@ int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu) return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE; } +/* + * This functions as an allow-list of protected VM capabilities. + * Features not explicitly allowed by this function are denied. + */ +static bool pkvm_ext_allowed(struct kvm *kvm, long ext) +{ + switch (ext) { + case KVM_CAP_IRQCHIP: + case KVM_CAP_ARM_PSCI: + case KVM_CAP_ARM_PSCI_0_2: + case KVM_CAP_NR_VCPUS: + case KVM_CAP_MAX_VCPUS: + case KVM_CAP_MAX_VCPU_ID: + case KVM_CAP_MSI_DEVID: + case KVM_CAP_ARM_VM_IPA_SIZE: + case KVM_CAP_ARM_PMU_V3: + case KVM_CAP_ARM_SVE: + case KVM_CAP_ARM_PTRAUTH_ADDRESS: + case KVM_CAP_ARM_PTRAUTH_GENERIC: + return true; + default: + return false; + } +} + int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) { @@ -78,6 +103,9 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, if (cap->flags) return -EINVAL; + if (kvm_vm_is_protected(kvm) && !pkvm_ext_allowed(kvm, cap->cap)) + return -EINVAL; + switch (cap->cap) { case KVM_CAP_ARM_NISV_TO_USER: r = 0; @@ -250,6 +278,10 @@ static bool kvm_has_full_ptr_auth(void) int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) { int r; + + if (kvm && kvm_vm_is_protected(kvm) && !pkvm_ext_allowed(kvm, ext)) + return 0; + switch (ext) { case KVM_CAP_IRQCHIP: r = vgic_present; -- 2.44.0.769.g3c40516874-goog