KVM: arm64: introduce vcpu->arch.debug_ptr

This introduces a level of indirection for the debug registers. Instead
of using the sys_regs[] directly we store registers in a structure in
the vcpu. The new kvm_arm_reset_debug_ptr() sets the debug ptr to the
guest context.

Because we no longer give the sys_regs offset for the sys_reg_desc->reg
field, but instead the index into a debug-specific struct we need to
add a number of additional trap functions for each register. Also as the
generic generic user-space access code no longer works we have
introduced a new pair of function pointers to the sys_reg_desc structure
to override the generic code when needed.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 2b0bc8c..dcba0fa 100644 (file)
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -234,5 +234,6 @@ 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) {}
+static inline void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) {}
 
 #endif /* __ARM_KVM_HOST_H__ */

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 77151b1..9ce5cf0 100644 (file)
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -278,6 +278,8 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
        /* Set up the timer */
        kvm_timer_vcpu_init(vcpu);
 
+       kvm_arm_reset_debug_ptr(vcpu);
+
        return 0;
 }
 

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index f5e40da..67fa0de 100644 (file)
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -46,24 +46,16 @@
 #define        CNTKCTL_EL1     20      /* Timer Control Register (EL1) */
 #define        PAR_EL1         21      /* Physical Address Register */
 #define MDSCR_EL1      22      /* Monitor Debug System Control Register */
-#define DBGBCR0_EL1    23      /* Debug Breakpoint Control Registers (0-15) */
-#define DBGBCR15_EL1   38
-#define DBGBVR0_EL1    39      /* Debug Breakpoint Value Registers (0-15) */
-#define DBGBVR15_EL1   54
-#define DBGWCR0_EL1    55      /* Debug Watchpoint Control Registers (0-15) */
-#define DBGWCR15_EL1   70
-#define DBGWVR0_EL1    71      /* Debug Watchpoint Value Registers (0-15) */
-#define DBGWVR15_EL1   86
-#define MDCCINT_EL1    87      /* Monitor Debug Comms Channel Interrupt Enable Reg */
+#define MDCCINT_EL1    23      /* Monitor Debug Comms Channel Interrupt Enable Reg */
 
 /* 32bit specific registers. Keep them at the end of the range */
-#define        DACR32_EL2      88      /* Domain Access Control Register */
-#define        IFSR32_EL2      89      /* Instruction Fault Status Register */
-#define        FPEXC32_EL2     90      /* Floating-Point Exception Control Register */
-#define        DBGVCR32_EL2    91      /* Debug Vector Catch Register */
-#define        TEECR32_EL1     92      /* ThumbEE Configuration Register */
-#define        TEEHBR32_EL1    93      /* ThumbEE Handler Base Register */
-#define        NR_SYS_REGS     94
+#define        DACR32_EL2      24      /* Domain Access Control Register */
+#define        IFSR32_EL2      25      /* Instruction Fault Status Register */
+#define        FPEXC32_EL2     26      /* Floating-Point Exception Control Register */
+#define        DBGVCR32_EL2    27      /* Debug Vector Catch Register */
+#define        TEECR32_EL1     28      /* ThumbEE Configuration Register */
+#define        TEEHBR32_EL1    29      /* ThumbEE Handler Base Register */
+#define        NR_SYS_REGS     30
 
 /* 32bit mapping */
 #define c0_MPIDR       (MPIDR_EL1 * 2) /* MultiProcessor ID Register */

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index cfb6754..9b99402 100644 (file)
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -108,11 +108,25 @@ struct kvm_vcpu_arch {
        /* Exception Information */
        struct kvm_vcpu_fault_info fault;
 
-       /* Debug state */
+       /* Guest debug state */
        u64 debug_flags;
 
+       /*
+        * We maintain more than a single set of debug registers to support
+        * debugging the guest from the host and to maintain separate host and
+        * guest state during world switches. vcpu_debug_state are the debug
+        * registers of the vcpu as the guest sees them.  host_debug_state are
+        * the host registers which are saved and restored during world switches.
+        *
+        * debug_ptr points to the set of debug registers that should be loaded
+        * onto the hardware when running the guest.
+        */
+       struct kvm_guest_debug_arch *debug_ptr;
+       struct kvm_guest_debug_arch vcpu_debug_state;
+
        /* Pointer to host CPU context */
        kvm_cpu_context_t *host_cpu_context;
+       struct kvm_guest_debug_arch host_debug_state;
 
        /* VGIC state */
        struct vgic_cpu vgic_cpu;
@@ -242,5 +256,6 @@ 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);
+void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu);
 
 #endif /* __ARM64_KVM_HOST_H__ */

diff --cc arch/arm64/kernel/asm-offsets.c
Simple merge

diff --cc arch/arm64/kvm/debug.c
Simple merge

diff --cc arch/arm64/kvm/hyp.S
Simple merge

diff --cc arch/arm64/kvm/sys_regs.c
Simple merge

diff --cc arch/arm64/kvm/sys_regs.h
Simple merge