arm: better error reporting and panic dump

This patch adds exhaustive handling of hypervisor errors, and the
ability to stop and park CPUs after dumping their EL1 context, when they
encounter an unhandled trap.

Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
[Jan: Adjustments to recent control subsystem changes]
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

diff --git a/hypervisor/arch/arm/control.c b/hypervisor/arch/arm/control.c
index 27af483059413d5d7718f47256909a6c58032298..2bb1ae640f6b5fdae9ebaf81c487ccea8ca64aac 100644 (file)
--- a/hypervisor/arch/arm/control.c
+++ b/hypervisor/arch/arm/control.c
@@ -12,6 +12,7 @@
 
 #include <jailhouse/control.h>
 #include <jailhouse/printk.h>
+#include <jailhouse/processor.h>
 #include <jailhouse/string.h>
 #include <asm/control.h>
 #include <asm/irqchip.h>
@@ -139,6 +140,28 @@ static void arch_suspend_self(struct per_cpu *cpu_data)
                arch_cpu_tlb_flush(cpu_data);
 }
 
+static void arch_dump_exit(const char *reason)
+{
+       unsigned long pc;
+
+       arm_read_banked_reg(ELR_hyp, pc);
+       printk("Unhandled HYP %s exit at 0x%x\n", reason, pc);
+}
+
+static void arch_dump_abt(bool is_data)
+{
+       u32 hxfar;
+       u32 esr;
+
+       arm_read_sysreg(ESR_EL2, esr);
+       if (is_data)
+               arm_read_sysreg(HDFAR, hxfar);
+       else
+               arm_read_sysreg(HIFAR, hxfar);
+
+       printk("  paddr=0x%lx esr=0x%x\n", hxfar, esr);
+}
+
 struct registers* arch_handle_exit(struct per_cpu *cpu_data,
                                   struct registers *regs)
 {
@@ -149,10 +172,27 @@ struct registers* arch_handle_exit(struct per_cpu *cpu_data,
        case EXIT_REASON_TRAP:
                arch_handle_trap(cpu_data, regs);
                break;
+
+       case EXIT_REASON_UNDEF:
+               arch_dump_exit("undef");
+               panic_stop();
+       case EXIT_REASON_DABT:
+               arch_dump_exit("data abort");
+               arch_dump_abt(true);
+               panic_stop();
+       case EXIT_REASON_PABT:
+               arch_dump_exit("prefetch abort");
+               arch_dump_abt(false);
+               panic_stop();
+       case EXIT_REASON_HVC:
+               arch_dump_exit("hvc");
+               panic_stop();
+       case EXIT_REASON_FIQ:
+               arch_dump_exit("fiq");
+               panic_stop();
        default:
-               printk("Internal error: %d exit not implemented\n",
-                               regs->exit_reason);
-               while(1);
+               arch_dump_exit("unknown");
+               panic_stop();
        }
 
        return regs;
@@ -260,3 +300,19 @@ void arch_flush_cell_vcpu_caches(struct cell *cell)
 void arch_config_commit(struct cell *cell_added_removed)
 {
 }
+
+void arch_panic_stop(void)
+{
+       psci_cpu_off(this_cpu_data());
+       __builtin_unreachable();
+}
+
+void arch_panic_park(void)
+{
+       /* Won't return to panic_park */
+       if (phys_processor_id() == panic_cpu)
+               panic_in_progress = 0;
+
+       psci_cpu_off(this_cpu_data());
+       __builtin_unreachable();
+}

diff --git a/hypervisor/arch/arm/exception.S b/hypervisor/arch/arm/exception.S
index 6190098753a233174037320b9284ad2a37aa8707..ede7a132a42522f26828270dfe527e783f4e8bb4 100644 (file)
--- a/hypervisor/arch/arm/exception.S
+++ b/hypervisor/arch/arm/exception.S
@@ -19,13 +19,13 @@
        .align 5
 hyp_vectors:
        b       .
-       b       .
-       b       .
-       b       .
-       b       .
+       b       hyp_undef
+       b       hyp_hvc
+       b       hyp_pabt
+       b       hyp_dabt
        b       hyp_trap
        b       hyp_irq
-       b       .
+       b       hyp_fiq
 
 .macro handle_vmexit exit_reason
        /* Fill the struct registers. Should comply with NUM_USR_REGS */
@@ -34,8 +34,19 @@ hyp_vectors:
        b       vmexit_common
 .endm
 
+hyp_undef:
+       handle_vmexit EXIT_REASON_UNDEF
+hyp_hvc:
+       handle_vmexit EXIT_REASON_HVC
+hyp_pabt:
+       handle_vmexit EXIT_REASON_PABT
+hyp_dabt:
+       handle_vmexit EXIT_REASON_DABT
+
 hyp_irq:
        handle_vmexit EXIT_REASON_IRQ
+hyp_fiq:
+       handle_vmexit EXIT_REASON_FIQ
 hyp_trap:
        handle_vmexit EXIT_REASON_TRAP
 

diff --git a/hypervisor/arch/arm/include/asm/processor.h b/hypervisor/arch/arm/include/asm/processor.h
index 0dbd4dfaa42a8c2984065333d16dd477f6200471..049a838a44f2b376d8e172f5c3b5db7c0471d25e 100644 (file)
--- a/hypervisor/arch/arm/include/asm/processor.h
+++ b/hypervisor/arch/arm/include/asm/processor.h
@@ -142,8 +142,13 @@
 #define ESR_ICC_CV_BIT         (1 << 24)
 #define ESR_ICC_COND(icc)      ((icc) >> 20 & 0xf)
 
-#define EXIT_REASON_TRAP       0x1
-#define EXIT_REASON_IRQ                0x2
+#define EXIT_REASON_UNDEF      0x1
+#define EXIT_REASON_HVC                0x2
+#define EXIT_REASON_PABT       0x3
+#define EXIT_REASON_DABT       0x4
+#define EXIT_REASON_TRAP       0x5
+#define EXIT_REASON_IRQ                0x6
+#define EXIT_REASON_FIQ                0x7
 
 #define NUM_USR_REGS           14
 

diff --git a/hypervisor/arch/arm/include/asm/sysregs.h b/hypervisor/arch/arm/include/asm/sysregs.h
index 1f9abeb4881771360c7028724d9976fe1079182c..47607561f84b2e807c16089a54a2d1d5aba51410 100644 (file)
--- a/hypervisor/arch/arm/include/asm/sysregs.h
+++ b/hypervisor/arch/arm/include/asm/sysregs.h
@@ -69,6 +69,9 @@
 #define VBAR           SYSREG_32(0, c12, c0, 0)
 #define HCR            SYSREG_32(4, c1, c1, 0)
 #define HCR2           SYSREG_32(4, c1, c1, 4)
+#define HDFAR          SYSREG_32(4, c6, c0, 0)
+#define HIFAR          SYSREG_32(4, c6, c0, 2)
+#define HPFAR          SYSREG_32(4, c6, c0, 4)
 #define HMAIR0         SYSREG_32(4, c10, c2, 0)
 #define HMAIR1         SYSREG_32(4, c10, c2, 1)
 #define HVBAR          SYSREG_32(4, c12, c0, 0)

diff --git a/hypervisor/arch/arm/setup.c b/hypervisor/arch/arm/setup.c
index ef408a8afbd9a5642a472dbf04a33260f1714e70..120d82f0547d41beb0d5906fc0ec20ab8c29a364 100644 (file)
--- a/hypervisor/arch/arm/setup.c
+++ b/hypervisor/arch/arm/setup.c
@@ -121,5 +121,3 @@ void arch_cpu_restore(struct per_cpu *cpu_data)
 // catch missing symbols
 void arch_shutdown_cpu(unsigned int cpu_id) {}
 void arch_shutdown(void) {}
-void arch_panic_stop(void) {__builtin_unreachable();}
-void arch_panic_park(void) {}

diff --git a/hypervisor/arch/arm/traps.c b/hypervisor/arch/arm/traps.c
index 8dc5ab57bbb445081fdda2d5429e60fda20acac0..6c8e788e82e7889011d11d45e276616121796120 100644 (file)
--- a/hypervisor/arch/arm/traps.c
+++ b/hypervisor/arch/arm/traps.c
@@ -188,6 +188,22 @@ static void access_cell_reg(struct trap_context *ctx, u8 reg,
        }
 }
 
+static void dump_guest_regs(struct per_cpu *cpu_data, struct trap_context *ctx)
+{
+       u8 reg;
+       unsigned long reg_val;
+
+       panic_printk("pc=0x%08x cpsr=0x%08x esr=0x%08x\n", ctx->pc, ctx->cpsr,
+                       ctx->esr);
+       for (reg = 0; reg < 15; reg++) {
+               access_cell_reg(ctx, reg, &reg_val, true);
+               panic_printk("r%d=0x%08x ", reg, reg_val);
+               if ((reg + 1) % 4 == 0)
+                       panic_printk("\n");
+       }
+       panic_printk("\n");
+}
+
 static int arch_handle_hvc(struct per_cpu *cpu_data, struct trap_context *ctx)
 {
        unsigned long *regs = ctx->regs;
@@ -257,10 +273,14 @@ void arch_handle_trap(struct per_cpu *cpu_data, struct registers *guest_regs)
        if (trap_handlers[exception_class])
                ret = trap_handlers[exception_class](cpu_data, &ctx);
 
-       if (ret != TRAP_HANDLED) {
-               panic_printk("CPU%d: Unhandled HYP trap, syndrome 0x%x\n",
-                               cpu_data->cpu_id, ctx.esr);
-               while(1);
+       switch (ret) {
+       case TRAP_UNHANDLED:
+       case TRAP_FORBIDDEN:
+               panic_printk("FATAL: %s on CPU%d\n", (ret == TRAP_UNHANDLED ?
+                               "unhandled trap" : "forbidden access"),
+                               cpu_data->cpu_id);
+               dump_guest_regs(cpu_data, &ctx);
+               panic_park();
        }
 
 restore_context: