From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (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 8B8453399A for ; Tue, 19 Sep 2023 17:50:32 +0000 (UTC) Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-274b736caf3so2660688a91.2 for ; Tue, 19 Sep 2023 10:50:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1695145832; x=1695750632; 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=WDqS9gCK2hWJbMjalAxBpmnQXFt//tHeeybGxVMKHYk=; b=k1KUX8hO7uPkSqIg1pl6qvS9NIUaftfii9IPBLa/ePl5M8+ubNaHdhmg7kMbxSUfqX jvrjCoDQ5pF1RsA3bsJCDrD9b9AI+ZekwWlS6VIMdXds0gMoTl8ghlDJWwhdMo8+cUUx tqebPm4mhAHLeYsDbjiMW+7j3iSeqSLISAjCG1qeM7TzIxGYN0Rj15YSoRxaKkcoWoty CaqDiONOBTMuye/E43w/wKKJbDux6NSUxJ15aFzJsYci+pncC0Q1JMxzJXYx47KIfUYE c5A60PVBY7JAc2t2l67ktljbge5o/1PP7ne7aR0SkiCcp857m0KZOkSroN60XHAmJ/Ja zheg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695145832; x=1695750632; 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=WDqS9gCK2hWJbMjalAxBpmnQXFt//tHeeybGxVMKHYk=; b=iZrV6ltbQgxEkEaj0vX5s5irai/2JT9mJeXaEXc8GH11M/mGlg6LuGjzP7UTN1rCtT k270RBPvtpArcQMmP6RN/aCE/CwY4iyLKGjQ8Yq5Jb/Axn1RLxFNk/MOMiLlFjKvHB9K hj6y9+m98QObTobY9a2gKkbP620gqtoOpr8GbeTZU/gdBbrezIDFRmeyWzKBL+uXSNQ6 IAojl/vpqMlU3JzNdLl5+0c1+zR2W/w3nvd35xqGF9Gq/8TtnOcY3OFENcrYT7w2zTuJ a5TUW5137Y08JjOvBxo+P7fpH/8Bq5/GwmtW40dZpfT1iHVxjEYIy2looyVQPKaLOm8X mv5w== X-Gm-Message-State: AOJu0YzwaU5apYQxh0KoMu2E5SwzSBJBgt+WCpa5HAhRe/wQUDmmpTeG g6ZB5txVjgj4uDthWjR1K5fU9Cfdxs91V7EqSw== X-Google-Smtp-Source: AGHT+IFN34HCsWwHcm0VPaYd7vZlKFFWGc9Vo3Vmh+MXi2TsekzYPzoQupklZxM0iu6EWzoGRPjs/bXawpslssLVYQ== X-Received: from jgzg.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:1acf]) (user=jingzhangos job=sendgmr) by 2002:a17:90a:fa12:b0:268:1d63:b9ae with SMTP id cm18-20020a17090afa1200b002681d63b9aemr8189pjb.3.1695145831933; Tue, 19 Sep 2023 10:50:31 -0700 (PDT) Date: Tue, 19 Sep 2023 10:50:16 -0700 In-Reply-To: <20230919175017.538312-1-jingzhangos@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20230919175017.538312-1-jingzhangos@google.com> X-Mailer: git-send-email 2.42.0.459.ge4e396fd5e-goog Message-ID: <20230919175017.538312-5-jingzhangos@google.com> Subject: [PATCH v1 4/4] KVM: arm64: Reject attempts to set invalid debug arch version From: Jing Zhang To: KVM , KVMARM , ARMLinux , Marc Zyngier , Oliver Upton Cc: Will Deacon , Paolo Bonzini , James Morse , Alexandru Elisei , Suzuki K Poulose , Fuad Tabba , Suraj Jitindar Singh , Cornelia Huck , Shaoqin Huang , Jing Zhang Content-Type: text/plain; charset="UTF-8" From: Oliver Upton The debug architecture is mandatory in ARMv8, so KVM should not allow userspace to configure a vCPU with less than that. Of course, this isn't handled elegantly by the generic ID register plumbing, as the respective ID register fields have a nonzero starting value. Add an explicit check for debug versions less than v8 of the architecture. Signed-off-by: Oliver Upton Signed-off-by: Jing Zhang --- arch/arm64/kvm/sys_regs.c | 32 +++++++++++++++++++++++++++++--- 1 file changed, 29 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 4dcc9272fbb8..fdebd9d042c3 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1216,8 +1216,14 @@ static s64 kvm_arm64_ftr_safe_value(u32 id, const struct arm64_ftr_bits *ftrp, /* Some features have different safe value type in KVM than host features */ switch (id) { case SYS_ID_AA64DFR0_EL1: - if (kvm_ftr.shift == ID_AA64DFR0_EL1_PMUVer_SHIFT) + switch (kvm_ftr.shift) { + case ID_AA64DFR0_EL1_PMUVer_SHIFT: kvm_ftr.type = FTR_LOWER_SAFE; + break; + case ID_AA64DFR0_EL1_DebugVer_SHIFT: + kvm_ftr.type = FTR_LOWER_SAFE; + break; + } break; case SYS_ID_DFR0_EL1: if (kvm_ftr.shift == ID_DFR0_EL1_PerfMon_SHIFT) @@ -1476,14 +1482,22 @@ static u64 read_sanitised_id_aa64pfr0_el1(struct kvm_vcpu *vcpu, return val; } +#define ID_REG_LIMIT_FIELD_ENUM(val, reg, field, limit) \ +({ \ + u64 __f_val = FIELD_GET(reg##_##field##_MASK, val); \ + (val) &= ~reg##_##field##_MASK; \ + (val) |= FIELD_PREP(reg##_##field##_MASK, \ + min(__f_val, (u64)reg##_##field##_##limit)); \ + (val); \ +}) + static u64 read_sanitised_id_aa64dfr0_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd) { u64 val = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1); /* Limit debug to ARMv8.0 */ - val &= ~ID_AA64DFR0_EL1_DebugVer_MASK; - val |= SYS_FIELD_PREP_ENUM(ID_AA64DFR0_EL1, DebugVer, IMP); + val = ID_REG_LIMIT_FIELD_ENUM(val, ID_AA64DFR0_EL1, DebugVer, IMP); /* * Only initialize the PMU version if the vCPU was configured with one. @@ -1503,6 +1517,7 @@ static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd, u64 val) { + u8 debugver = SYS_FIELD_GET(ID_AA64DFR0_EL1, DebugVer, val); u8 pmuver = SYS_FIELD_GET(ID_AA64DFR0_EL1, PMUVer, val); /* @@ -1522,6 +1537,13 @@ static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu, if (pmuver == ID_AA64DFR0_EL1_PMUVer_IMP_DEF) val &= ~ID_AA64DFR0_EL1_PMUVer_MASK; + /* + * ID_AA64DFR0_EL1.DebugVer is one of those awkward fields with a + * nonzero minimum safe value. + */ + if (debugver < ID_AA64DFR0_EL1_DebugVer_IMP) + return -EINVAL; + return set_id_reg(vcpu, rd, val); } @@ -1543,6 +1565,7 @@ static int set_id_dfr0_el1(struct kvm_vcpu *vcpu, u64 val) { u8 perfmon = SYS_FIELD_GET(ID_DFR0_EL1, PerfMon, val); + u8 copdbg = SYS_FIELD_GET(ID_DFR0_EL1, CopDbg, val); if (perfmon == ID_DFR0_EL1_PerfMon_IMPDEF) { val &= ~ID_DFR0_EL1_PerfMon_MASK; @@ -1558,6 +1581,9 @@ static int set_id_dfr0_el1(struct kvm_vcpu *vcpu, if (perfmon != 0 && perfmon < ID_DFR0_EL1_PerfMon_PMUv3) return -EINVAL; + if (copdbg < ID_DFR0_EL1_CopDbg_Armv8) + return -EINVAL; + return set_id_reg(vcpu, rd, val); } -- 2.42.0.459.ge4e396fd5e-goog