* [PATCH v2 1/2] KVM: arm64: Move pmu hyp code under hyp's Makefile to avoid instrumentation
2019-05-22 17:47 [PATCH v2 0/2] Move __hyp_text code under no-asan Makefiles James Morse
@ 2019-05-22 17:47 ` James Morse
2019-05-22 17:47 ` [PATCH v2 2/2] KVM: arm/arm64: Move cc/it checks " James Morse
1 sibling, 0 replies; 3+ messages in thread
From: James Morse @ 2019-05-22 17:47 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Suzuki K Pouloze, Marc Zyngier, Julien Thierry, Christoffer Dall,
James Morse, Andrew Murray
KVM's pmu.c contains the __hyp_text needed to switch the pmu registers
between host and guest. Because this isn't covered by the 'hyp' Makefile,
it can be built with kasan and friends when these are enabled in Kconfig.
When starting a guest, this results in:
| Kernel panic - not syncing: HYP panic:
| PS:a00003c9 PC:000083000028ada0 ESR:86000007
| FAR:000083000028ada0 HPFAR:0000000029df5300 PAR:0000000000000000
| VCPU:000000004e10b7d6
| CPU: 0 PID: 3088 Comm: qemu-system-aar Not tainted 5.2.0-rc1 #11026
| Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Plat
| Call trace:
| dump_backtrace+0x0/0x200
| show_stack+0x20/0x30
| dump_stack+0xec/0x158
| panic+0x1ec/0x420
| panic+0x0/0x420
| SMP: stopping secondary CPUs
| Kernel Offset: disabled
| CPU features: 0x002,25006082
| Memory Limit: none
| ---[ end Kernel panic - not syncing: HYP panic:
This is caused by functions in pmu.c calling the instrumented
code, which isn't mapped to hyp. From objdump -r:
| RELOCATION RECORDS FOR [.hyp.text]:
| OFFSET TYPE VALUE
| 0000000000000010 R_AARCH64_CALL26 __sanitizer_cov_trace_pc
| 0000000000000018 R_AARCH64_CALL26 __asan_load4_noabort
| 0000000000000024 R_AARCH64_CALL26 __asan_load4_noabort
Move the affected code to a new file under 'hyp's Makefile.
Fixes: 3d91befbb3a0 ("arm64: KVM: Enable !VHE support for :G/:H perf event modifiers")
Cc: Andrew Murray <Andrew.Murray@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
---
Changes since v1:
* Made the two functions static in patch 1, removed the header entries.
arch/arm64/include/asm/kvm_host.h | 3 ---
arch/arm64/kvm/hyp/switch.c | 39 +++++++++++++++++++++++++++++++
arch/arm64/kvm/pmu.c | 38 ------------------------------
3 files changed, 39 insertions(+), 41 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 2a8d3f8ca22c..4bcd9c1291d5 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -592,9 +592,6 @@ static inline int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr);
void kvm_clr_pmu_events(u32 clr);
-void __pmu_switch_to_host(struct kvm_cpu_context *host_ctxt);
-bool __pmu_switch_to_guest(struct kvm_cpu_context *host_ctxt);
-
void kvm_vcpu_pmu_restore_guest(struct kvm_vcpu *vcpu);
void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu);
#else
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 22b4c335e0b2..8799e0c267d4 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -16,6 +16,7 @@
*/
#include <linux/arm-smccc.h>
+#include <linux/kvm_host.h>
#include <linux/types.h>
#include <linux/jump_label.h>
#include <uapi/linux/psci.h>
@@ -505,6 +506,44 @@ static void __hyp_text __set_host_arch_workaround_state(struct kvm_vcpu *vcpu)
#endif
}
+/**
+ * Disable host events, enable guest events
+ */
+static bool __hyp_text __pmu_switch_to_guest(struct kvm_cpu_context *host_ctxt)
+{
+ struct kvm_host_data *host;
+ struct kvm_pmu_events *pmu;
+
+ host = container_of(host_ctxt, struct kvm_host_data, host_ctxt);
+ pmu = &host->pmu_events;
+
+ if (pmu->events_host)
+ write_sysreg(pmu->events_host, pmcntenclr_el0);
+
+ if (pmu->events_guest)
+ write_sysreg(pmu->events_guest, pmcntenset_el0);
+
+ return (pmu->events_host || pmu->events_guest);
+}
+
+/**
+ * Disable guest events, enable host events
+ */
+static void __hyp_text __pmu_switch_to_host(struct kvm_cpu_context *host_ctxt)
+{
+ struct kvm_host_data *host;
+ struct kvm_pmu_events *pmu;
+
+ host = container_of(host_ctxt, struct kvm_host_data, host_ctxt);
+ pmu = &host->pmu_events;
+
+ if (pmu->events_guest)
+ write_sysreg(pmu->events_guest, pmcntenclr_el0);
+
+ if (pmu->events_host)
+ write_sysreg(pmu->events_host, pmcntenset_el0);
+}
+
/* Switch to the guest for VHE systems running in EL2 */
int kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
{
diff --git a/arch/arm64/kvm/pmu.c b/arch/arm64/kvm/pmu.c
index 3da94a5bb6b7..e71d00bb5271 100644
--- a/arch/arm64/kvm/pmu.c
+++ b/arch/arm64/kvm/pmu.c
@@ -53,44 +53,6 @@ void kvm_clr_pmu_events(u32 clr)
ctx->pmu_events.events_guest &= ~clr;
}
-/**
- * Disable host events, enable guest events
- */
-bool __hyp_text __pmu_switch_to_guest(struct kvm_cpu_context *host_ctxt)
-{
- struct kvm_host_data *host;
- struct kvm_pmu_events *pmu;
-
- host = container_of(host_ctxt, struct kvm_host_data, host_ctxt);
- pmu = &host->pmu_events;
-
- if (pmu->events_host)
- write_sysreg(pmu->events_host, pmcntenclr_el0);
-
- if (pmu->events_guest)
- write_sysreg(pmu->events_guest, pmcntenset_el0);
-
- return (pmu->events_host || pmu->events_guest);
-}
-
-/**
- * Disable guest events, enable host events
- */
-void __hyp_text __pmu_switch_to_host(struct kvm_cpu_context *host_ctxt)
-{
- struct kvm_host_data *host;
- struct kvm_pmu_events *pmu;
-
- host = container_of(host_ctxt, struct kvm_host_data, host_ctxt);
- pmu = &host->pmu_events;
-
- if (pmu->events_guest)
- write_sysreg(pmu->events_guest, pmcntenclr_el0);
-
- if (pmu->events_host)
- write_sysreg(pmu->events_host, pmcntenset_el0);
-}
-
#define PMEVTYPER_READ_CASE(idx) \
case idx: \
return read_sysreg(pmevtyper##idx##_el0)
--
2.20.1
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 3+ messages in thread* [PATCH v2 2/2] KVM: arm/arm64: Move cc/it checks under hyp's Makefile to avoid instrumentation
2019-05-22 17:47 [PATCH v2 0/2] Move __hyp_text code under no-asan Makefiles James Morse
2019-05-22 17:47 ` [PATCH v2 1/2] KVM: arm64: Move pmu hyp code under hyp's Makefile to avoid instrumentation James Morse
@ 2019-05-22 17:47 ` James Morse
1 sibling, 0 replies; 3+ messages in thread
From: James Morse @ 2019-05-22 17:47 UTC (permalink / raw)
To: linux-arm-kernel, kvmarm
Cc: Suzuki K Pouloze, Marc Zyngier, Julien Thierry, Christoffer Dall,
James Morse, Andrew Murray
KVM has helpers to handle the condition codes of trapped aarch32
instructions. These are marked __hyp_text and used from HYP, but they
aren't built by the 'hyp' Makefile, which has all the runes to avoid ASAN
and KCOV instrumentation.
Move this code to a new hyp/aarch32.c to avoid a hyp-panic when starting
an aarch32 guest on a host built with the ASAN/KCOV debug options.
Fixes: 021234ef3752f ("KVM: arm64: Make kvm_condition_valid32() accessible from EL2")
Fixes: 8cebe750c4d9a ("arm64: KVM: Make kvm_skip_instr32 available to HYP")
Signed-off-by: James Morse <james.morse@arm.com>
---
arch/arm/kvm/hyp/Makefile | 1 +
arch/arm64/kvm/hyp/Makefile | 1 +
virt/kvm/arm/aarch32.c | 121 --------------------------------
virt/kvm/arm/hyp/aarch32.c | 136 ++++++++++++++++++++++++++++++++++++
4 files changed, 138 insertions(+), 121 deletions(-)
create mode 100644 virt/kvm/arm/hyp/aarch32.c
diff --git a/arch/arm/kvm/hyp/Makefile b/arch/arm/kvm/hyp/Makefile
index d2b5ec9c4b92..ba88b1eca93c 100644
--- a/arch/arm/kvm/hyp/Makefile
+++ b/arch/arm/kvm/hyp/Makefile
@@ -11,6 +11,7 @@ CFLAGS_ARMV7VE :=$(call cc-option, -march=armv7ve)
obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/vgic-v3-sr.o
obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/timer-sr.o
+obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/aarch32.o
obj-$(CONFIG_KVM_ARM_HOST) += tlb.o
obj-$(CONFIG_KVM_ARM_HOST) += cp15-sr.o
diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
index 82d1904328ad..ea710f674cb6 100644
--- a/arch/arm64/kvm/hyp/Makefile
+++ b/arch/arm64/kvm/hyp/Makefile
@@ -10,6 +10,7 @@ KVM=../../../../virt/kvm
obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/vgic-v3-sr.o
obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/timer-sr.o
+obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/aarch32.o
obj-$(CONFIG_KVM_ARM_HOST) += vgic-v2-cpuif-proxy.o
obj-$(CONFIG_KVM_ARM_HOST) += sysreg-sr.o
diff --git a/virt/kvm/arm/aarch32.c b/virt/kvm/arm/aarch32.c
index 5abbe9b3c652..6880236974b8 100644
--- a/virt/kvm/arm/aarch32.c
+++ b/virt/kvm/arm/aarch32.c
@@ -25,127 +25,6 @@
#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>
-/*
- * stolen from arch/arm/kernel/opcodes.c
- *
- * condition code lookup table
- * index into the table is test code: EQ, NE, ... LT, GT, AL, NV
- *
- * bit position in short is condition code: NZCV
- */
-static const unsigned short cc_map[16] = {
- 0xF0F0, /* EQ == Z set */
- 0x0F0F, /* NE */
- 0xCCCC, /* CS == C set */
- 0x3333, /* CC */
- 0xFF00, /* MI == N set */
- 0x00FF, /* PL */
- 0xAAAA, /* VS == V set */
- 0x5555, /* VC */
- 0x0C0C, /* HI == C set && Z clear */
- 0xF3F3, /* LS == C clear || Z set */
- 0xAA55, /* GE == (N==V) */
- 0x55AA, /* LT == (N!=V) */
- 0x0A05, /* GT == (!Z && (N==V)) */
- 0xF5FA, /* LE == (Z || (N!=V)) */
- 0xFFFF, /* AL always */
- 0 /* NV */
-};
-
-/*
- * Check if a trapped instruction should have been executed or not.
- */
-bool __hyp_text kvm_condition_valid32(const struct kvm_vcpu *vcpu)
-{
- unsigned long cpsr;
- u32 cpsr_cond;
- int cond;
-
- /* Top two bits non-zero? Unconditional. */
- if (kvm_vcpu_get_hsr(vcpu) >> 30)
- return true;
-
- /* Is condition field valid? */
- cond = kvm_vcpu_get_condition(vcpu);
- if (cond == 0xE)
- return true;
-
- cpsr = *vcpu_cpsr(vcpu);
-
- if (cond < 0) {
- /* This can happen in Thumb mode: examine IT state. */
- unsigned long it;
-
- it = ((cpsr >> 8) & 0xFC) | ((cpsr >> 25) & 0x3);
-
- /* it == 0 => unconditional. */
- if (it == 0)
- return true;
-
- /* The cond for this insn works out as the top 4 bits. */
- cond = (it >> 4);
- }
-
- cpsr_cond = cpsr >> 28;
-
- if (!((cc_map[cond] >> cpsr_cond) & 1))
- return false;
-
- return true;
-}
-
-/**
- * adjust_itstate - adjust ITSTATE when emulating instructions in IT-block
- * @vcpu: The VCPU pointer
- *
- * When exceptions occur while instructions are executed in Thumb IF-THEN
- * blocks, the ITSTATE field of the CPSR is not advanced (updated), so we have
- * to do this little bit of work manually. The fields map like this:
- *
- * IT[7:0] -> CPSR[26:25],CPSR[15:10]
- */
-static void __hyp_text kvm_adjust_itstate(struct kvm_vcpu *vcpu)
-{
- unsigned long itbits, cond;
- unsigned long cpsr = *vcpu_cpsr(vcpu);
- bool is_arm = !(cpsr & PSR_AA32_T_BIT);
-
- if (is_arm || !(cpsr & PSR_AA32_IT_MASK))
- return;
-
- cond = (cpsr & 0xe000) >> 13;
- itbits = (cpsr & 0x1c00) >> (10 - 2);
- itbits |= (cpsr & (0x3 << 25)) >> 25;
-
- /* Perform ITAdvance (see page A2-52 in ARM DDI 0406C) */
- if ((itbits & 0x7) == 0)
- itbits = cond = 0;
- else
- itbits = (itbits << 1) & 0x1f;
-
- cpsr &= ~PSR_AA32_IT_MASK;
- cpsr |= cond << 13;
- cpsr |= (itbits & 0x1c) << (10 - 2);
- cpsr |= (itbits & 0x3) << 25;
- *vcpu_cpsr(vcpu) = cpsr;
-}
-
-/**
- * kvm_skip_instr - skip a trapped instruction and proceed to the next
- * @vcpu: The vcpu pointer
- */
-void __hyp_text kvm_skip_instr32(struct kvm_vcpu *vcpu, bool is_wide_instr)
-{
- bool is_thumb;
-
- is_thumb = !!(*vcpu_cpsr(vcpu) & PSR_AA32_T_BIT);
- if (is_thumb && !is_wide_instr)
- *vcpu_pc(vcpu) += 2;
- else
- *vcpu_pc(vcpu) += 4;
- kvm_adjust_itstate(vcpu);
-}
-
/*
* Table taken from ARMv8 ARM DDI0487B-B, table G1-10.
*/
diff --git a/virt/kvm/arm/hyp/aarch32.c b/virt/kvm/arm/hyp/aarch32.c
new file mode 100644
index 000000000000..d31f267961e7
--- /dev/null
+++ b/virt/kvm/arm/hyp/aarch32.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Hyp portion of the (not much of an) Emulation layer for 32bit guests.
+ *
+ * Copyright (C) 2012,2013 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * based on arch/arm/kvm/emulate.c
+ * Copyright (C) 2012 - Virtual Open Systems and Columbia University
+ * Author: Christoffer Dall <c.dall@virtualopensystems.com>
+ */
+
+#include <linux/kvm_host.h>
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_hyp.h>
+
+/*
+ * stolen from arch/arm/kernel/opcodes.c
+ *
+ * condition code lookup table
+ * index into the table is test code: EQ, NE, ... LT, GT, AL, NV
+ *
+ * bit position in short is condition code: NZCV
+ */
+static const unsigned short cc_map[16] = {
+ 0xF0F0, /* EQ == Z set */
+ 0x0F0F, /* NE */
+ 0xCCCC, /* CS == C set */
+ 0x3333, /* CC */
+ 0xFF00, /* MI == N set */
+ 0x00FF, /* PL */
+ 0xAAAA, /* VS == V set */
+ 0x5555, /* VC */
+ 0x0C0C, /* HI == C set && Z clear */
+ 0xF3F3, /* LS == C clear || Z set */
+ 0xAA55, /* GE == (N==V) */
+ 0x55AA, /* LT == (N!=V) */
+ 0x0A05, /* GT == (!Z && (N==V)) */
+ 0xF5FA, /* LE == (Z || (N!=V)) */
+ 0xFFFF, /* AL always */
+ 0 /* NV */
+};
+
+/*
+ * Check if a trapped instruction should have been executed or not.
+ */
+bool __hyp_text kvm_condition_valid32(const struct kvm_vcpu *vcpu)
+{
+ unsigned long cpsr;
+ u32 cpsr_cond;
+ int cond;
+
+ /* Top two bits non-zero? Unconditional. */
+ if (kvm_vcpu_get_hsr(vcpu) >> 30)
+ return true;
+
+ /* Is condition field valid? */
+ cond = kvm_vcpu_get_condition(vcpu);
+ if (cond == 0xE)
+ return true;
+
+ cpsr = *vcpu_cpsr(vcpu);
+
+ if (cond < 0) {
+ /* This can happen in Thumb mode: examine IT state. */
+ unsigned long it;
+
+ it = ((cpsr >> 8) & 0xFC) | ((cpsr >> 25) & 0x3);
+
+ /* it == 0 => unconditional. */
+ if (it == 0)
+ return true;
+
+ /* The cond for this insn works out as the top 4 bits. */
+ cond = (it >> 4);
+ }
+
+ cpsr_cond = cpsr >> 28;
+
+ if (!((cc_map[cond] >> cpsr_cond) & 1))
+ return false;
+
+ return true;
+}
+
+/**
+ * adjust_itstate - adjust ITSTATE when emulating instructions in IT-block
+ * @vcpu: The VCPU pointer
+ *
+ * When exceptions occur while instructions are executed in Thumb IF-THEN
+ * blocks, the ITSTATE field of the CPSR is not advanced (updated), so we have
+ * to do this little bit of work manually. The fields map like this:
+ *
+ * IT[7:0] -> CPSR[26:25],CPSR[15:10]
+ */
+static void __hyp_text kvm_adjust_itstate(struct kvm_vcpu *vcpu)
+{
+ unsigned long itbits, cond;
+ unsigned long cpsr = *vcpu_cpsr(vcpu);
+ bool is_arm = !(cpsr & PSR_AA32_T_BIT);
+
+ if (is_arm || !(cpsr & PSR_AA32_IT_MASK))
+ return;
+
+ cond = (cpsr & 0xe000) >> 13;
+ itbits = (cpsr & 0x1c00) >> (10 - 2);
+ itbits |= (cpsr & (0x3 << 25)) >> 25;
+
+ /* Perform ITAdvance (see page A2-52 in ARM DDI 0406C) */
+ if ((itbits & 0x7) == 0)
+ itbits = cond = 0;
+ else
+ itbits = (itbits << 1) & 0x1f;
+
+ cpsr &= ~PSR_AA32_IT_MASK;
+ cpsr |= cond << 13;
+ cpsr |= (itbits & 0x1c) << (10 - 2);
+ cpsr |= (itbits & 0x3) << 25;
+ *vcpu_cpsr(vcpu) = cpsr;
+}
+
+/**
+ * kvm_skip_instr - skip a trapped instruction and proceed to the next
+ * @vcpu: The vcpu pointer
+ */
+void __hyp_text kvm_skip_instr32(struct kvm_vcpu *vcpu, bool is_wide_instr)
+{
+ bool is_thumb;
+
+ is_thumb = !!(*vcpu_cpsr(vcpu) & PSR_AA32_T_BIT);
+ if (is_thumb && !is_wide_instr)
+ *vcpu_pc(vcpu) += 2;
+ else
+ *vcpu_pc(vcpu) += 4;
+ kvm_adjust_itstate(vcpu);
+}
--
2.20.1
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^ permalink raw reply related [flat|nested] 3+ messages in thread