From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-61.mta1.migadu.com (out-61.mta1.migadu.com [95.215.58.61]) (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 D6E16125A4 for ; Fri, 23 Jun 2023 20:52:49 +0000 (UTC) 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=1687553567; 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; bh=NSzW7IRCJ+9VbfTRACIuf9UJCqUm/pAsMsRJ3jyCJ04=; b=L8LgEOtuZinEO09//wym3WXMI7fobKlZXRaQ0W3C1BFF1NHXdC81iXMmTylwABVodWE7MU HV5Aki1gdi52hWjqpFtuzm3lIDtsGgZe2KKoob0mFGhhPBvPtMwJ4D4jNKUdd2ZInWd0AO PagYj2hM0AjcET+5i0AT0kW9TT8XE7s= From: Oliver Upton To: kvmarm@lists.linux.dev Cc: Marc Zyngier , James Morse , Suzuki K Poulose , Zenghui Yu , Jing Zhang , Reiji Watanabe , Oliver Upton Subject: [PATCH] KVM: arm64: Reject attempts to set invalid debug arch version Date: Fri, 23 Jun 2023 20:52:32 +0000 Message-ID: <20230623205232.2837077-1-oliver.upton@linux.dev> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT 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. Fixes: c118cead07a7 ("KVM: arm64: Use generic sanitisation for ID_(AA64)DFR0_EL1") Signed-off-by: Oliver Upton --- arch/arm64/kvm/sys_regs.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 1a13bab1a06c..5b25053a8e04 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1482,6 +1482,7 @@ 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); /* @@ -1501,6 +1502,13 @@ 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); } @@ -1522,6 +1530,7 @@ 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; @@ -1537,6 +1546,9 @@ 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); } base-commit: 192df2aa0113ddddee2a93e453ff46610807b425 -- 2.41.0.178.g377b9f9a00-goog