[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v2] exec.c: Fix subpage memory access to RAM Mem
From: |
Andreas Färber |
Subject: |
Re: [Qemu-devel] [PATCH v2] exec.c: Fix subpage memory access to RAM MemoryRegion |
Date: |
Wed, 22 Aug 2012 18:53:19 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120713 Thunderbird/14.0 |
Am 15.12.2011 19:09, schrieb Anthony Liguori:
> On 11/30/2011 09:26 AM, Andreas Färber wrote:
>> Commit 95c318f5e1f88d7e5bcc6deac17330fd4806a2d3 (Fix segfault in mmio
>> subpage handling code.) prevented a segfault by making all subpage
>> registrations over an existing memory page perform an unassigned access.
>> Symptoms were writes not taking effect and reads returning zero.
>>
>> Very small page sizes are not currently supported either,
>> so subpage memory areas cannot fully be avoided.
>>
>> Therefore change the previous fix to use a new IO_MEM_SUBPAGE_RAM
>> instead of IO_MEM_UNASSIGNED. Suggested by Avi.
>>
>> Signed-off-by: Andreas Färber<address@hidden>
>> Cc: Avi Kivity<address@hidden>
>> Cc: Gleb Natapov<address@hidden>
>
> Applied. Thanks.
Applied to stable-0.15.
Andreas
> Regards,
>
> Anthony Liguori
>
>> ---
>> cpu-common.h | 1 +
>> exec.c | 65
>> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
>> 2 files changed, 64 insertions(+), 2 deletions(-)
>>
>> diff --git a/cpu-common.h b/cpu-common.h
>> index c9878ba..3f45428 100644
>> --- a/cpu-common.h
>> +++ b/cpu-common.h
>> @@ -172,6 +172,7 @@ void
>> cpu_physical_memory_write_rom(target_phys_addr_t addr,
>> #define IO_MEM_ROM (1<< IO_MEM_SHIFT) /* hardcoded offset */
>> #define IO_MEM_UNASSIGNED (2<< IO_MEM_SHIFT)
>> #define IO_MEM_NOTDIRTY (3<< IO_MEM_SHIFT)
>> +#define IO_MEM_SUBPAGE_RAM (4<< IO_MEM_SHIFT)
>>
>> /* Acts like a ROM when read and like a device when written. */
>> #define IO_MEM_ROMD (1)
>> diff --git a/exec.c b/exec.c
>> index 6b92198..6c206ff 100644
>> --- a/exec.c
>> +++ b/exec.c
>> @@ -3570,6 +3570,63 @@ static CPUWriteMemoryFunc * const
>> subpage_write[] = {
>> &subpage_writel,
>> };
>>
>> +static uint32_t subpage_ram_readb(void *opaque, target_phys_addr_t addr)
>> +{
>> + ram_addr_t raddr = addr;
>> + void *ptr = qemu_get_ram_ptr(raddr);
>> + return ldub_p(ptr);
>> +}
>> +
>> +static void subpage_ram_writeb(void *opaque, target_phys_addr_t addr,
>> + uint32_t value)
>> +{
>> + ram_addr_t raddr = addr;
>> + void *ptr = qemu_get_ram_ptr(raddr);
>> + stb_p(ptr, value);
>> +}
>> +
>> +static uint32_t subpage_ram_readw(void *opaque, target_phys_addr_t addr)
>> +{
>> + ram_addr_t raddr = addr;
>> + void *ptr = qemu_get_ram_ptr(raddr);
>> + return lduw_p(ptr);
>> +}
>> +
>> +static void subpage_ram_writew(void *opaque, target_phys_addr_t addr,
>> + uint32_t value)
>> +{
>> + ram_addr_t raddr = addr;
>> + void *ptr = qemu_get_ram_ptr(raddr);
>> + stw_p(ptr, value);
>> +}
>> +
>> +static uint32_t subpage_ram_readl(void *opaque, target_phys_addr_t addr)
>> +{
>> + ram_addr_t raddr = addr;
>> + void *ptr = qemu_get_ram_ptr(raddr);
>> + return ldl_p(ptr);
>> +}
>> +
>> +static void subpage_ram_writel(void *opaque, target_phys_addr_t addr,
>> + uint32_t value)
>> +{
>> + ram_addr_t raddr = addr;
>> + void *ptr = qemu_get_ram_ptr(raddr);
>> + stl_p(ptr, value);
>> +}
>> +
>> +static CPUReadMemoryFunc * const subpage_ram_read[] = {
>> +&subpage_ram_readb,
>> +&subpage_ram_readw,
>> +&subpage_ram_readl,
>> +};
>> +
>> +static CPUWriteMemoryFunc * const subpage_ram_write[] = {
>> +&subpage_ram_writeb,
>> +&subpage_ram_writew,
>> +&subpage_ram_writel,
>> +};
>> +
>> static int subpage_register (subpage_t *mmio, uint32_t start,
>> uint32_t end,
>> ram_addr_t memory, ram_addr_t
>> region_offset)
>> {
>> @@ -3583,8 +3640,9 @@ static int subpage_register (subpage_t *mmio,
>> uint32_t start, uint32_t end,
>> printf("%s: %p start %08x end %08x idx %08x eidx %08x mem
>> %ld\n", __func__,
>> mmio, start, end, idx, eidx, memory);
>> #endif
>> - if ((memory& ~TARGET_PAGE_MASK) == IO_MEM_RAM)
>> - memory = IO_MEM_UNASSIGNED;
>> + if ((memory& ~TARGET_PAGE_MASK) == IO_MEM_RAM) {
>> + memory = IO_MEM_SUBPAGE_RAM;
>> + }
>> memory = (memory>> IO_MEM_SHIFT)& (IO_MEM_NB_ENTRIES - 1);
>> for (; idx<= eidx; idx++) {
>> mmio->sub_io_index[idx] = memory;
>> @@ -3817,6 +3875,9 @@ static void io_mem_init(void)
>> cpu_register_io_memory_fixed(IO_MEM_NOTDIRTY, error_mem_read,
>> notdirty_mem_write, NULL,
>> DEVICE_NATIVE_ENDIAN);
>> + cpu_register_io_memory_fixed(IO_MEM_SUBPAGE_RAM, subpage_ram_read,
>> + subpage_ram_write, NULL,
>> + DEVICE_NATIVE_ENDIAN);
>> for (i=0; i<5; i++)
>> io_mem_used[i] = 1;
>>
--
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- Re: [Qemu-devel] [PATCH v2] exec.c: Fix subpage memory access to RAM MemoryRegion,
Andreas Färber <=