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-rw-r--r--arch/arm64/include/asm/kvm_arm.h3
-rw-r--r--arch/arm64/include/asm/kvm_host.h1
-rw-r--r--arch/arm64/kvm/debug.c21
-rw-r--r--arch/arm64/kvm/handle_exit.c57
-rw-r--r--arch/arm64/kvm/hyp/switch.c37
5 files changed, 95 insertions, 24 deletions
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 7f069ff37f06..715d395ef45b 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -170,8 +170,7 @@
#define VTCR_EL2_FLAGS (VTCR_EL2_COMMON_BITS | VTCR_EL2_TGRAN_FLAGS)
#define VTTBR_X (VTTBR_X_TGRAN_MAGIC - VTCR_EL2_T0SZ_IPA)
-#define VTTBR_BADDR_SHIFT (VTTBR_X - 1)
-#define VTTBR_BADDR_MASK (((UL(1) << (PHYS_MASK_SHIFT - VTTBR_X)) - 1) << VTTBR_BADDR_SHIFT)
+#define VTTBR_BADDR_MASK (((UL(1) << (PHYS_MASK_SHIFT - VTTBR_X)) - 1) << VTTBR_X)
#define VTTBR_VMID_SHIFT (UL(48))
#define VTTBR_VMID_MASK(size) (_AT(u64, (1 << size) - 1) << VTTBR_VMID_SHIFT)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 674912d7a571..ea6cb5b24258 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -370,6 +370,7 @@ void kvm_arm_init_debug(void);
void kvm_arm_setup_debug(struct kvm_vcpu *vcpu);
void kvm_arm_clear_debug(struct kvm_vcpu *vcpu);
void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu);
+bool kvm_arm_handle_step_debug(struct kvm_vcpu *vcpu, struct kvm_run *run);
int kvm_arm_vcpu_arch_set_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr);
int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu,
diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
index dbadfaf850a7..fa63b28c65e0 100644
--- a/arch/arm64/kvm/debug.c
+++ b/arch/arm64/kvm/debug.c
@@ -221,3 +221,24 @@ void kvm_arm_clear_debug(struct kvm_vcpu *vcpu)
}
}
}
+
+
+/*
+ * After successfully emulating an instruction, we might want to
+ * return to user space with a KVM_EXIT_DEBUG. We can only do this
+ * once the emulation is complete, though, so for userspace emulations
+ * we have to wait until we have re-entered KVM before calling this
+ * helper.
+ *
+ * Return true (and set exit_reason) to return to userspace or false
+ * if no further action is required.
+ */
+bool kvm_arm_handle_step_debug(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+ if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) {
+ run->exit_reason = KVM_EXIT_DEBUG;
+ run->debug.arch.hsr = ESR_ELx_EC_SOFTSTP_LOW << ESR_ELx_EC_SHIFT;
+ return true;
+ }
+ return false;
+}
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index b71247995469..304203fa9e33 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -28,6 +28,7 @@
#include <asm/kvm_emulate.h>
#include <asm/kvm_mmu.h>
#include <asm/kvm_psci.h>
+#include <asm/debug-monitors.h>
#define CREATE_TRACE_POINTS
#include "trace.h"
@@ -187,14 +188,46 @@ static exit_handle_fn kvm_get_exit_handler(struct kvm_vcpu *vcpu)
}
/*
+ * We may be single-stepping an emulated instruction. If the emulation
+ * has been completed in the kernel, we can return to userspace with a
+ * KVM_EXIT_DEBUG, otherwise userspace needs to complete its
+ * emulation first.
+ */
+static int handle_trap_exceptions(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+ int handled;
+
+ /*
+ * See ARM ARM B1.14.1: "Hyp traps on instructions
+ * that fail their condition code check"
+ */
+ if (!kvm_condition_valid(vcpu)) {
+ kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
+ handled = 1;
+ } else {
+ exit_handle_fn exit_handler;
+
+ exit_handler = kvm_get_exit_handler(vcpu);
+ handled = exit_handler(vcpu, run);
+ }
+
+ /*
+ * kvm_arm_handle_step_debug() sets the exit_reason on the kvm_run
+ * structure if we need to return to userspace.
+ */
+ if (handled > 0 && kvm_arm_handle_step_debug(vcpu, run))
+ handled = 0;
+
+ return handled;
+}
+
+/*
* Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
* proper exit to userspace.
*/
int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
int exception_index)
{
- exit_handle_fn exit_handler;
-
if (ARM_SERROR_PENDING(exception_index)) {
u8 hsr_ec = ESR_ELx_EC(kvm_vcpu_get_hsr(vcpu));
@@ -220,20 +253,14 @@ int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
return 1;
case ARM_EXCEPTION_EL1_SERROR:
kvm_inject_vabt(vcpu);
- return 1;
- case ARM_EXCEPTION_TRAP:
- /*
- * See ARM ARM B1.14.1: "Hyp traps on instructions
- * that fail their condition code check"
- */
- if (!kvm_condition_valid(vcpu)) {
- kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
+ /* We may still need to return for single-step */
+ if (!(*vcpu_cpsr(vcpu) & DBG_SPSR_SS)
+ && kvm_arm_handle_step_debug(vcpu, run))
+ return 0;
+ else
return 1;
- }
-
- exit_handler = kvm_get_exit_handler(vcpu);
-
- return exit_handler(vcpu, run);
+ case ARM_EXCEPTION_TRAP:
+ return handle_trap_exceptions(vcpu, run);
case ARM_EXCEPTION_HYP_GONE:
/*
* EL2 has been reset to the hyp-stub. This happens when a guest
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 525c01f48867..f7c651f3a8c0 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -22,6 +22,7 @@
#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>
#include <asm/fpsimd.h>
+#include <asm/debug-monitors.h>
static bool __hyp_text __fpsimd_enabled_nvhe(void)
{
@@ -269,7 +270,11 @@ static bool __hyp_text __populate_fault_info(struct kvm_vcpu *vcpu)
return true;
}
-static void __hyp_text __skip_instr(struct kvm_vcpu *vcpu)
+/* Skip an instruction which has been emulated. Returns true if
+ * execution can continue or false if we need to exit hyp mode because
+ * single-step was in effect.
+ */
+static bool __hyp_text __skip_instr(struct kvm_vcpu *vcpu)
{
*vcpu_pc(vcpu) = read_sysreg_el2(elr);
@@ -282,6 +287,14 @@ static void __hyp_text __skip_instr(struct kvm_vcpu *vcpu)
}
write_sysreg_el2(*vcpu_pc(vcpu), elr);
+
+ if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) {
+ vcpu->arch.fault.esr_el2 =
+ (ESR_ELx_EC_SOFTSTP_LOW << ESR_ELx_EC_SHIFT) | 0x22;
+ return false;
+ } else {
+ return true;
+ }
}
int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu)
@@ -342,13 +355,21 @@ again:
int ret = __vgic_v2_perform_cpuif_access(vcpu);
if (ret == 1) {
- __skip_instr(vcpu);
- goto again;
+ if (__skip_instr(vcpu))
+ goto again;
+ else
+ exit_code = ARM_EXCEPTION_TRAP;
}
if (ret == -1) {
- /* Promote an illegal access to an SError */
- __skip_instr(vcpu);
+ /* Promote an illegal access to an
+ * SError. If we would be returning
+ * due to single-step clear the SS
+ * bit so handle_exit knows what to
+ * do after dealing with the error.
+ */
+ if (!__skip_instr(vcpu))
+ *vcpu_cpsr(vcpu) &= ~DBG_SPSR_SS;
exit_code = ARM_EXCEPTION_EL1_SERROR;
}
@@ -363,8 +384,10 @@ again:
int ret = __vgic_v3_perform_cpuif_access(vcpu);
if (ret == 1) {
- __skip_instr(vcpu);
- goto again;
+ if (__skip_instr(vcpu))
+ goto again;
+ else
+ exit_code = ARM_EXCEPTION_TRAP;
}
/* 0 falls through to be handled out of EL2 */
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-24 20:18:05 +0000