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-rw-r--r--arch/arm/include/asm/kvm_host.h4
-rw-r--r--arch/arm/kvm/arm.c6
-rw-r--r--arch/arm64/include/asm/kvm_asm.h2
-rw-r--r--arch/arm64/include/asm/kvm_host.h5
-rw-r--r--arch/arm64/kernel/asm-offsets.c1
-rw-r--r--arch/arm64/kvm/Makefile2
-rw-r--r--arch/arm64/kvm/debug.c81
-rw-r--r--arch/arm64/kvm/hyp.S19
8 files changed, 108 insertions, 12 deletions
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index e896d2c196e6..2b0bc8c57552 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -231,4 +231,8 @@ static inline void kvm_arch_sync_events(struct kvm *kvm) {}
static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
+static inline void kvm_arm_init_debug(void) {}
+static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) {}
+
#endif /* __ARM_KVM_HOST_H__ */
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 1b693cb2d5b2..77151b111d32 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -543,6 +543,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
continue;
}
+ kvm_arm_setup_debug(vcpu);
+
/**************************************************************
* Enter the guest
*/
@@ -557,6 +559,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
* Back from guest
*************************************************************/
+ kvm_arm_clear_debug(vcpu);
+
/*
* We may have taken a host interrupt in HYP mode (ie
* while executing the guest). This interrupt is still
@@ -914,6 +918,8 @@ static void cpu_init_hyp_mode(void *dummy)
vector_ptr = (unsigned long)__kvm_hyp_vector;
__cpu_init_hyp_mode(boot_pgd_ptr, pgd_ptr, hyp_stack_ptr, vector_ptr);
+
+ kvm_arm_init_debug();
}
static int hyp_init_cpu_notify(struct notifier_block *self,
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 3c5fe685a2d6..f5e40dae291a 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -132,6 +132,8 @@ extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
extern u64 __vgic_v3_get_ich_vtr_el2(void);
+extern u32 __kvm_get_mdcr_el2(void);
+
#endif
#endif /* __ARM_KVM_ASM_H__ */
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 2709db2a7eac..c90c6a41c448 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -103,6 +103,7 @@ struct kvm_vcpu_arch {
/* HYP configuration */
u64 hcr_el2;
+ u32 mdcr_el2;
/* Exception Information */
struct kvm_vcpu_fault_info fault;
@@ -227,4 +228,8 @@ static inline void kvm_arch_sync_events(struct kvm *kvm) {}
static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
+void kvm_arm_init_debug(void);
+void kvm_arm_setup_debug(struct kvm_vcpu *vcpu);
+void kvm_arm_clear_debug(struct kvm_vcpu *vcpu);
+
#endif /* __ARM64_KVM_HOST_H__ */
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index c99701a34d7b..5c900d49b906 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -117,6 +117,7 @@ int main(void)
DEFINE(VCPU_HPFAR_EL2, offsetof(struct kvm_vcpu, arch.fault.hpfar_el2));
DEFINE(VCPU_DEBUG_FLAGS, offsetof(struct kvm_vcpu, arch.debug_flags));
DEFINE(VCPU_HCR_EL2, offsetof(struct kvm_vcpu, arch.hcr_el2));
+ DEFINE(VCPU_MDCR_EL2, offsetof(struct kvm_vcpu, arch.mdcr_el2));
DEFINE(VCPU_IRQ_LINES, offsetof(struct kvm_vcpu, arch.irq_lines));
DEFINE(VCPU_HOST_CONTEXT, offsetof(struct kvm_vcpu, arch.host_cpu_context));
DEFINE(VCPU_TIMER_CNTV_CTL, offsetof(struct kvm_vcpu, arch.timer_cpu.cntv_ctl));
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index f90f4aa7f88d..1949fe5f5424 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -17,7 +17,7 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(ARM)/psci.o $(ARM)/perf.o
kvm-$(CONFIG_KVM_ARM_HOST) += emulate.o inject_fault.o regmap.o
kvm-$(CONFIG_KVM_ARM_HOST) += hyp.o hyp-init.o handle_exit.o
-kvm-$(CONFIG_KVM_ARM_HOST) += guest.o reset.o sys_regs.o sys_regs_generic_v8.o
+kvm-$(CONFIG_KVM_ARM_HOST) += guest.o debug.o reset.o sys_regs.o sys_regs_generic_v8.o
kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic.o
kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic-v2.o
diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
new file mode 100644
index 000000000000..faf0e1fdba9e
--- /dev/null
+++ b/arch/arm64/kvm/debug.c
@@ -0,0 +1,81 @@
+/*
+ * Debug and Guest Debug support
+ *
+ * Copyright (C) 2015 - Linaro Ltd
+ * Author: Alex Bennée <alex.bennee@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/kvm_host.h>
+
+#include <asm/kvm_arm.h>
+
+static DEFINE_PER_CPU(u32, mdcr_el2);
+
+/**
+ * kvm_arm_init_debug - grab what we need for debug
+ *
+ * Currently the sole task of this function is to retrieve the initial
+ * value of mdcr_el2 so we can preserve MDCR_EL2.HPMN which has
+ * presumably been set-up by some knowledgeable bootcode.
+ *
+ * It is called once per-cpu during CPU hyp initialisation.
+ */
+
+void kvm_arm_init_debug(void)
+{
+ __this_cpu_write(mdcr_el2, kvm_call_hyp(__kvm_get_mdcr_el2));
+}
+
+
+/**
+ * kvm_arm_setup_debug - set up debug related stuff
+ *
+ * @vcpu: the vcpu pointer
+ *
+ * This is called before each entry into the hypervisor to setup any
+ * debug related registers. Currently this just ensures we will trap
+ * access to:
+ * - Performance monitors (MDCR_EL2_TPM/MDCR_EL2_TPMCR)
+ * - Debug ROM Address (MDCR_EL2_TDRA)
+ * - OS related registers (MDCR_EL2_TDOSA)
+ *
+ * Additionally, KVM only traps guest accesses to the debug registers if
+ * the guest is not actively using them (see the KVM_ARM64_DEBUG_DIRTY
+ * flag on vcpu->arch.debug_flags). Since the guest must not interfere
+ * with the hardware state when debugging the guest, we must ensure that
+ * trapping is enabled whenever we are debugging the guest using the
+ * debug registers.
+ */
+
+void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
+{
+ bool trap_debug = !(vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY);
+
+ vcpu->arch.mdcr_el2 = __this_cpu_read(mdcr_el2) & MDCR_EL2_HPMN_MASK;
+ vcpu->arch.mdcr_el2 |= (MDCR_EL2_TPM |
+ MDCR_EL2_TPMCR |
+ MDCR_EL2_TDRA |
+ MDCR_EL2_TDOSA);
+
+ /* Trap on access to debug registers? */
+ if (trap_debug)
+ vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA;
+
+}
+
+void kvm_arm_clear_debug(struct kvm_vcpu *vcpu)
+{
+ /* Nothing to do yet */
+}
diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
index 17a8fb14f428..b3176e6e51d1 100644
--- a/arch/arm64/kvm/hyp.S
+++ b/arch/arm64/kvm/hyp.S
@@ -770,17 +770,8 @@
mov x2, #(1 << 15) // Trap CP15 Cr=15
msr hstr_el2, x2
- mrs x2, mdcr_el2
- and x2, x2, #MDCR_EL2_HPMN_MASK
- orr x2, x2, #(MDCR_EL2_TPM | MDCR_EL2_TPMCR)
- orr x2, x2, #(MDCR_EL2_TDRA | MDCR_EL2_TDOSA)
-
- // Check for KVM_ARM64_DEBUG_DIRTY, and set debug to trap
- // if not dirty.
- ldr x3, [x0, #VCPU_DEBUG_FLAGS]
- tbnz x3, #KVM_ARM64_DEBUG_DIRTY_SHIFT, 1f
- orr x2, x2, #MDCR_EL2_TDA
-1:
+ // Monitor Debug Config - see kvm_arm_setup_debug()
+ ldr x2, [x0, #VCPU_MDCR_EL2]
msr mdcr_el2, x2
.endm
@@ -1285,4 +1276,10 @@ ENTRY(__kvm_hyp_vector)
ventry el1_error_invalid // Error 32-bit EL1
ENDPROC(__kvm_hyp_vector)
+
+ENTRY(__kvm_get_mdcr_el2)
+ mrs x0, mdcr_el2
+ ret
+ENDPROC(__kvm_get_mdcr_el2)
+
.popsection
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-01 01:57:28 +0000