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[Qemu-devel] [PULL 10/11] mips jazz: do not raise data bus exception whe
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 10/11] mips jazz: do not raise data bus exception when accessing invalid addresses |
Date: |
Thu, 21 Nov 2013 17:49:37 +0100 |
From: Hervé Poussineau <address@hidden>
MIPS Jazz chipset doesn't seem to raise data bus exceptions on invalid accesses.
However, there is no easy way to prevent them. Creating a big memory region
for the whole address space doesn't prevent memory core to directly call
unassigned_mem_read/write which in turn call cpu->do_unassigned_access,
which (for MIPS CPU) raise an data bus exception.
This fixes a MIPS Jazz regression introduced in
c658b94f6e8c206c59d02aa6fbac285b86b53d2c.
Signed-off-by: Hervé Poussineau <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
hw/mips/mips_jazz.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/hw/mips/mips_jazz.c b/hw/mips/mips_jazz.c
index 49bdd02..5f6dd9f 100644
--- a/hw/mips/mips_jazz.c
+++ b/hw/mips/mips_jazz.c
@@ -108,6 +108,18 @@ static void cpu_request_exit(void *opaque, int irq, int
level)
}
}
+static CPUUnassignedAccess real_do_unassigned_access;
+static void mips_jazz_do_unassigned_access(CPUState *cpu, hwaddr addr,
+ bool is_write, bool is_exec,
+ int opaque, unsigned size)
+{
+ if (!is_exec) {
+ /* ignore invalid access (ie do not raise exception) */
+ return;
+ }
+ (*real_do_unassigned_access)(cpu, addr, is_write, is_exec, opaque, size);
+}
+
static void mips_jazz_init(MemoryRegion *address_space,
MemoryRegion *address_space_io,
ram_addr_t ram_size,
@@ -117,6 +129,7 @@ static void mips_jazz_init(MemoryRegion *address_space,
char *filename;
int bios_size, n;
MIPSCPU *cpu;
+ CPUClass *cc;
CPUMIPSState *env;
qemu_irq *rc4030, *i8259;
rc4030_dma *dmas;
@@ -154,6 +167,17 @@ static void mips_jazz_init(MemoryRegion *address_space,
env = &cpu->env;
qemu_register_reset(main_cpu_reset, cpu);
+ /* Chipset returns 0 in invalid reads and do not raise data exceptions.
+ * However, we can't simply add a global memory region to catch
+ * everything, as memory core directly call unassigned_mem_read/write
+ * on some invalid accesses, which call do_unassigned_access on the
+ * CPU, which raise an exception.
+ * Handle that case by hijacking the do_unassigned_access method on
+ * the CPU, and do not raise exceptions for data access. */
+ cc = CPU_GET_CLASS(cpu);
+ real_do_unassigned_access = cc->do_unassigned_access;
+ cc->do_unassigned_access = mips_jazz_do_unassigned_access;
+
/* allocate RAM */
memory_region_init_ram(ram, NULL, "mips_jazz.ram", ram_size);
vmstate_register_ram_global(ram);
--
1.8.3.1
- [Qemu-devel] [PULL for-1.7 00/11] Miscellaneous -rc patches, Paolo Bonzini, 2013/11/21
- [Qemu-devel] [PULL 01/11] sun4m: Add FCode ROM for TCX framebuffer, Paolo Bonzini, 2013/11/21
- [Qemu-devel] [PULL 02/11] configure: Explicitly set ARFLAGS so we can build with GNU Make 4.0, Paolo Bonzini, 2013/11/21
- [Qemu-devel] [PULL 04/11] atomic.h: Fix build with clang, Paolo Bonzini, 2013/11/21
- [Qemu-devel] [PULL 06/11] target-i386: Fix build by providing stub kvm_arch_get_supported_cpuid(), Paolo Bonzini, 2013/11/21
- [Qemu-devel] [PULL 05/11] vfio-pci: Fix multifunction=on, Paolo Bonzini, 2013/11/21
- [Qemu-devel] [PULL 08/11] rng-egd: offset the point when repeatedly read from the buffer, Paolo Bonzini, 2013/11/21
- [Qemu-devel] [PULL 09/11] target-i386: yield to another VCPU on PAUSE, Paolo Bonzini, 2013/11/21
- [Qemu-devel] [PULL 07/11] rng-egd: remove redundant free, Paolo Bonzini, 2013/11/21
- [Qemu-devel] [PULL 10/11] mips jazz: do not raise data bus exception when accessing invalid addresses,
Paolo Bonzini <=
- [Qemu-devel] [PULL 11/11] qga: Fix compiler warnings (missing format attribute, wrong format strings), Paolo Bonzini, 2013/11/21
- [Qemu-devel] [PULL 03/11] pc: get rid of builtin pvpanic for "-M pc-1.5", Paolo Bonzini, 2013/11/21
- Re: [Qemu-devel] [PULL for-1.7 00/11] Miscellaneous -rc patches, Paolo Bonzini, 2013/11/25