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From: Ionela Voinescu <ionela.voinescu@arm.com>
To: catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com,
	maz@kernel.org, suzuki.poulose@arm.com, sudeep.holla@arm.com,
	lukasz.luba@arm.com, valentin.schneider@arm.com,
	rjw@rjwysocki.net, ionela.voinescu@arm.com
Cc: peterz@infradead.org, mingo@redhat.com,
	vincent.guittot@linaro.org, viresh.kumar@linaro.org,
	linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
	James Morse <james.morse@arm.com>,
	Julien Thierry <julien.thierry.kdev@gmail.com>
Subject: [PATCH v3 3/7] arm64/kvm: disable access to AMU registers from kvm guests
Date: Tue, 11 Feb 2020 18:45:38 +0000	[thread overview]
Message-ID: <20200211184542.29585-4-ionela.voinescu@arm.com> (raw)
In-Reply-To: <20200211184542.29585-1-ionela.voinescu@arm.com>

Access to the AMU counters should be disabled by default in kvm guests,
as information from the counters might reveal activity in other guests
or activity on the host.

Therefore, disable access to AMU registers from EL0 and EL1 in kvm
guests by:
 - Hiding the presence of the extension in the feature register
   (SYS_ID_AA64PFR0_EL1) on the VCPU.
 - Disabling access to the AMU registers before switching to the guest.
 - Trapping accesses and injecting an undefined instruction into the
   guest.

Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
---
 arch/arm64/include/asm/kvm_arm.h |  1 +
 arch/arm64/kvm/hyp/switch.c      | 14 ++++-
 arch/arm64/kvm/sys_regs.c        | 93 +++++++++++++++++++++++++++++++-
 3 files changed, 105 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 6e5d839f42b5..51c1d9918999 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -267,6 +267,7 @@
 
 /* Hyp Coprocessor Trap Register */
 #define CPTR_EL2_TCPAC	(1 << 31)
+#define CPTR_EL2_TAM	(1 << 30)
 #define CPTR_EL2_TTA	(1 << 20)
 #define CPTR_EL2_TFP	(1 << CPTR_EL2_TFP_SHIFT)
 #define CPTR_EL2_TZ	(1 << 8)
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 72fbbd86eb5e..11b43a365743 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -90,6 +90,18 @@ static void activate_traps_vhe(struct kvm_vcpu *vcpu)
 	val = read_sysreg(cpacr_el1);
 	val |= CPACR_EL1_TTA;
 	val &= ~CPACR_EL1_ZEN;
+
+	/*
+	 * With VHE (HCR.E2H == 1), accesses to CPACR_EL1 are routed to
+	 * CPTR_EL2. In general, CPACR_EL1 has the same layout as CPTR_EL2,
+	 * except for some missing controls, such as TAM.
+	 * In this case, CPTR_EL2.TAM has the same position with or without
+	 * VHE (HCR.E2H == 1) which allows us to use here the CPTR_EL2.TAM
+	 * shift value for trapping the AMU accesses.
+	 */
+
+	val |= CPTR_EL2_TAM;
+
 	if (update_fp_enabled(vcpu)) {
 		if (vcpu_has_sve(vcpu))
 			val |= CPACR_EL1_ZEN;
@@ -111,7 +123,7 @@ static void __hyp_text __activate_traps_nvhe(struct kvm_vcpu *vcpu)
 	__activate_traps_common(vcpu);
 
 	val = CPTR_EL2_DEFAULT;
-	val |= CPTR_EL2_TTA | CPTR_EL2_TZ;
+	val |= CPTR_EL2_TTA | CPTR_EL2_TZ | CPTR_EL2_TAM;
 	if (!update_fp_enabled(vcpu)) {
 		val |= CPTR_EL2_TFP;
 		__activate_traps_fpsimd32(vcpu);
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 9f2165937f7d..adeaa65a4cf0 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1003,6 +1003,20 @@ static bool access_pmuserenr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
 	{ SYS_DESC(SYS_PMEVTYPERn_EL0(n)),					\
 	  access_pmu_evtyper, reset_unknown, (PMEVTYPER0_EL0 + n), }
 
+static bool access_amu(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
+			     const struct sys_reg_desc *r)
+{
+	kvm_inject_undefined(vcpu);
+
+	return false;
+}
+
+/* Macro to expand the AMU counter and type registers*/
+#define AMU_AMEVCNTR0_EL0(n) { SYS_DESC(SYS_AMEVCNTR0_EL0(n)), access_amu }
+#define AMU_AMEVTYPE0_EL0(n) { SYS_DESC(SYS_AMEVTYPE0_EL0(n)), access_amu }
+#define AMU_AMEVCNTR1_EL0(n) { SYS_DESC(SYS_AMEVCNTR1_EL0(n)), access_amu }
+#define AMU_AMEVTYPE1_EL0(n) { SYS_DESC(SYS_AMEVTYPE1_EL0(n)), access_amu }
+
 static bool trap_ptrauth(struct kvm_vcpu *vcpu,
 			 struct sys_reg_params *p,
 			 const struct sys_reg_desc *rd)
@@ -1078,8 +1092,10 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu,
 			 (u32)r->CRn, (u32)r->CRm, (u32)r->Op2);
 	u64 val = raz ? 0 : read_sanitised_ftr_reg(id);
 
-	if (id == SYS_ID_AA64PFR0_EL1 && !vcpu_has_sve(vcpu)) {
-		val &= ~(0xfUL << ID_AA64PFR0_SVE_SHIFT);
+	if (id == SYS_ID_AA64PFR0_EL1) {
+		if (!vcpu_has_sve(vcpu))
+			val &= ~(0xfUL << ID_AA64PFR0_SVE_SHIFT);
+		val &= ~(0xfUL << ID_AA64PFR0_AMU_SHIFT);
 	} else if (id == SYS_ID_AA64ISAR1_EL1 && !vcpu_has_ptrauth(vcpu)) {
 		val &= ~((0xfUL << ID_AA64ISAR1_APA_SHIFT) |
 			 (0xfUL << ID_AA64ISAR1_API_SHIFT) |
@@ -1565,6 +1581,79 @@ static const struct sys_reg_desc sys_reg_descs[] = {
 	{ SYS_DESC(SYS_TPIDR_EL0), NULL, reset_unknown, TPIDR_EL0 },
 	{ SYS_DESC(SYS_TPIDRRO_EL0), NULL, reset_unknown, TPIDRRO_EL0 },
 
+	{ SYS_DESC(SYS_AMCR_EL0), access_amu },
+	{ SYS_DESC(SYS_AMCFGR_EL0), access_amu },
+	{ SYS_DESC(SYS_AMCGCR_EL0), access_amu },
+	{ SYS_DESC(SYS_AMUSERENR_EL0), access_amu },
+	{ SYS_DESC(SYS_AMCNTENCLR0_EL0), access_amu },
+	{ SYS_DESC(SYS_AMCNTENSET0_EL0), access_amu },
+	{ SYS_DESC(SYS_AMCNTENCLR1_EL0), access_amu },
+	{ SYS_DESC(SYS_AMCNTENSET1_EL0), access_amu },
+	AMU_AMEVCNTR0_EL0(0),
+	AMU_AMEVCNTR0_EL0(1),
+	AMU_AMEVCNTR0_EL0(2),
+	AMU_AMEVCNTR0_EL0(3),
+	AMU_AMEVCNTR0_EL0(4),
+	AMU_AMEVCNTR0_EL0(5),
+	AMU_AMEVCNTR0_EL0(6),
+	AMU_AMEVCNTR0_EL0(7),
+	AMU_AMEVCNTR0_EL0(8),
+	AMU_AMEVCNTR0_EL0(9),
+	AMU_AMEVCNTR0_EL0(10),
+	AMU_AMEVCNTR0_EL0(11),
+	AMU_AMEVCNTR0_EL0(12),
+	AMU_AMEVCNTR0_EL0(13),
+	AMU_AMEVCNTR0_EL0(14),
+	AMU_AMEVCNTR0_EL0(15),
+	AMU_AMEVTYPE0_EL0(0),
+	AMU_AMEVTYPE0_EL0(1),
+	AMU_AMEVTYPE0_EL0(2),
+	AMU_AMEVTYPE0_EL0(3),
+	AMU_AMEVTYPE0_EL0(4),
+	AMU_AMEVTYPE0_EL0(5),
+	AMU_AMEVTYPE0_EL0(6),
+	AMU_AMEVTYPE0_EL0(7),
+	AMU_AMEVTYPE0_EL0(8),
+	AMU_AMEVTYPE0_EL0(9),
+	AMU_AMEVTYPE0_EL0(10),
+	AMU_AMEVTYPE0_EL0(11),
+	AMU_AMEVTYPE0_EL0(12),
+	AMU_AMEVTYPE0_EL0(13),
+	AMU_AMEVTYPE0_EL0(14),
+	AMU_AMEVTYPE0_EL0(15),
+	AMU_AMEVCNTR1_EL0(0),
+	AMU_AMEVCNTR1_EL0(1),
+	AMU_AMEVCNTR1_EL0(2),
+	AMU_AMEVCNTR1_EL0(3),
+	AMU_AMEVCNTR1_EL0(4),
+	AMU_AMEVCNTR1_EL0(5),
+	AMU_AMEVCNTR1_EL0(6),
+	AMU_AMEVCNTR1_EL0(7),
+	AMU_AMEVCNTR1_EL0(8),
+	AMU_AMEVCNTR1_EL0(9),
+	AMU_AMEVCNTR1_EL0(10),
+	AMU_AMEVCNTR1_EL0(11),
+	AMU_AMEVCNTR1_EL0(12),
+	AMU_AMEVCNTR1_EL0(13),
+	AMU_AMEVCNTR1_EL0(14),
+	AMU_AMEVCNTR1_EL0(15),
+	AMU_AMEVTYPE1_EL0(0),
+	AMU_AMEVTYPE1_EL0(1),
+	AMU_AMEVTYPE1_EL0(2),
+	AMU_AMEVTYPE1_EL0(3),
+	AMU_AMEVTYPE1_EL0(4),
+	AMU_AMEVTYPE1_EL0(5),
+	AMU_AMEVTYPE1_EL0(6),
+	AMU_AMEVTYPE1_EL0(7),
+	AMU_AMEVTYPE1_EL0(8),
+	AMU_AMEVTYPE1_EL0(9),
+	AMU_AMEVTYPE1_EL0(10),
+	AMU_AMEVTYPE1_EL0(11),
+	AMU_AMEVTYPE1_EL0(12),
+	AMU_AMEVTYPE1_EL0(13),
+	AMU_AMEVTYPE1_EL0(14),
+	AMU_AMEVTYPE1_EL0(15),
+
 	{ SYS_DESC(SYS_CNTP_TVAL_EL0), access_arch_timer },
 	{ SYS_DESC(SYS_CNTP_CTL_EL0), access_arch_timer },
 	{ SYS_DESC(SYS_CNTP_CVAL_EL0), access_arch_timer },
-- 
2.17.1


  parent reply	other threads:[~2020-02-11 18:46 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-11 18:45 [PATCH v3 0/7] arm64: ARMv8.4 Activity Monitors support Ionela Voinescu
2020-02-11 18:45 ` [PATCH v3 1/7] arm64: add support for the AMU extension v1 Ionela Voinescu
2020-02-12 11:30   ` Suzuki Kuruppassery Poulose
2020-02-12 14:54     ` Valentin Schneider
2020-02-12 16:10     ` Ionela Voinescu
2020-02-12 16:20       ` Suzuki Kuruppassery Poulose
2020-02-12 18:20         ` Ionela Voinescu
2020-02-12 19:24           ` Suzuki K Poulose
2020-02-12 20:19         ` Ionela Voinescu
2020-02-12 16:24       ` Vladimir Murzin
2020-02-12 18:27         ` Ionela Voinescu
2020-02-11 18:45 ` [PATCH v3 2/7] arm64: trap to EL1 accesses to AMU counters from EL0 Ionela Voinescu
2020-02-12 11:44   ` Suzuki Kuruppassery Poulose
2020-02-12 15:36   ` Valentin Schneider
2020-02-11 18:45 ` Ionela Voinescu [this message]
2020-02-12 15:36   ` [PATCH v3 3/7] arm64/kvm: disable access to AMU registers from kvm guests Valentin Schneider
2020-02-12 16:33   ` Suzuki Kuruppassery Poulose
2020-02-11 18:45 ` [PATCH v3 4/7] Documentation: arm64: document support for the AMU extension Ionela Voinescu
2020-02-12 15:36   ` Valentin Schneider
2020-02-11 18:45 ` [PATCH v3 5/7] cpufreq: add function to get the hardware max frequency Ionela Voinescu
2020-02-12  4:14   ` Viresh Kumar
2020-02-13 11:59   ` Valentin Schneider
2020-02-13 12:59     ` Ionela Voinescu
2020-02-13 15:22       ` Valentin Schneider
2020-02-11 18:45 ` [PATCH v3 6/7] arm64: use activity monitors for frequency invariance Ionela Voinescu
2020-02-12 18:59   ` Lukasz Luba
2020-02-13  9:47     ` Ionela Voinescu
2020-02-17 16:59   ` Valentin Schneider
2020-02-23 18:49     ` Ionela Voinescu
2020-02-11 18:45 ` [PATCH v3 7/7] clocksource/drivers/arm_arch_timer: validate arch_timer_rate Ionela Voinescu
2020-02-12  9:30   ` Valentin Schneider
2020-02-12 10:32     ` Ionela Voinescu
2020-02-12 10:01   ` Lukasz Luba
2020-02-12 10:12     ` Marc Zyngier
2020-02-12 10:54       ` Ionela Voinescu
2020-02-12 10:55       ` Lukasz Luba
2020-02-12 11:10         ` Marc Zyngier
2020-02-12 11:43           ` Lukasz Luba
2020-02-12 11:12         ` Valentin Schneider
2020-02-14  0:35   ` Thomas Gleixner
2020-02-14 15:45     ` Ionela Voinescu
2020-02-14 15:57       ` Ionela Voinescu

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