Re: [Qemu-devel] [PATCH 2/2 v2][UPDATED] Direct IDE I/O
Paul Brook wrote: Unfortunately it is more complicated to write to the CPU memory. In particular, specific action should be done when translated code is present. A consistent API must include something like cpu_page_lock() / unlock(). Look at cpu_physical_memory_rw() to see the various issues which must be handled. Moreover, it would be better to add bus specific APIs (at least for PCI), but I can accept a CPU memory API for now. In general it may also be unsafe to do async writes directly to guest memory because you break the atomicity of loads/stores. But that is true on real hardware as well, I think. The guest cannot expect atomicity if it dmas into the memory it is accessing. Also, it would be a rare guest that accesses memory while dma is active. -- error compiling committee.c: too many arguments to function
Re: [Qemu-devel] [PATCH 2/2 v2][UPDATED] Direct IDE I/O
Le mardi 18 décembre 2007 à 00:03 +, Paul Brook a écrit : > On Monday 17 December 2007, Fabrice Bellard wrote: > > Laurent Vivier wrote: > > > This patch enhances the "-drive ,cache=off" mode with IDE drive emulation > > > by removing the buffer used in the IDE emulation. > > > --- > > > block.c | 10 +++ > > > block.h |2 > > > block_int.h |1 > > > cpu-all.h |1 > > > exec.c | 19 ++ > > > hw/ide.c| 176 > > > +--- vl.c > > > |1 > > > 7 files changed, 204 insertions(+), 6 deletions(-) > > > [...] > > > > Unfortunately it is more complicated to write to the CPU memory. In > > particular, specific action should be done when translated code is > > present. A consistent API must include something like cpu_page_lock() / > > unlock(). Look at cpu_physical_memory_rw() to see the various issues > > which must be handled. Moreover, it would be better to add bus specific > > APIs (at least for PCI), but I can accept a CPU memory API for now. > > In general it may also be unsafe to do async writes directly to guest memory > because you break the atomicity of loads/stores. Thank you for your comments. I had some doubts on this patch too. I will not resend it. I will resend only the first one corrected with comments from Fabrice (malloc()/free()). Regards, Laurent -- - [EMAIL PROTECTED] -- "La perfection est atteinte non quand il ne reste rien à ajouter mais quand il ne reste rien à enlever." Saint Exupéry signature.asc Description: Ceci est une partie de message numériquement signée
Re: [Qemu-devel] [PATCH 2/2 v2][UPDATED] Direct IDE I/O
On Monday 17 December 2007, Fabrice Bellard wrote: > Laurent Vivier wrote: > > This patch enhances the "-drive ,cache=off" mode with IDE drive emulation > > by removing the buffer used in the IDE emulation. > > --- > > block.c | 10 +++ > > block.h |2 > > block_int.h |1 > > cpu-all.h |1 > > exec.c | 19 ++ > > hw/ide.c| 176 > > +--- vl.c > > |1 > > 7 files changed, 204 insertions(+), 6 deletions(-) > > [...] > > Unfortunately it is more complicated to write to the CPU memory. In > particular, specific action should be done when translated code is > present. A consistent API must include something like cpu_page_lock() / > unlock(). Look at cpu_physical_memory_rw() to see the various issues > which must be handled. Moreover, it would be better to add bus specific > APIs (at least for PCI), but I can accept a CPU memory API for now. In general it may also be unsafe to do async writes directly to guest memory because you break the atomicity of loads/stores. Paul
Re: [Qemu-devel] [PATCH 2/2 v2][UPDATED] Direct IDE I/O
Laurent Vivier wrote: > This patch enhances the "-drive ,cache=off" mode with IDE drive emulation > by removing the buffer used in the IDE emulation. > --- > block.c | 10 +++ > block.h |2 > block_int.h |1 > cpu-all.h |1 > exec.c | 19 ++ > hw/ide.c| 176 > +--- > vl.c|1 > 7 files changed, 204 insertions(+), 6 deletions(-) > [...] Unfortunately it is more complicated to write to the CPU memory. In particular, specific action should be done when translated code is present. A consistent API must include something like cpu_page_lock() / unlock(). Look at cpu_physical_memory_rw() to see the various issues which must be handled. Moreover, it would be better to add bus specific APIs (at least for PCI), but I can accept a CPU memory API for now. Fabrice.
[Qemu-devel] [PATCH 2/2 v2][UPDATED] Direct IDE I/O
This patch enhances the "-drive ,cache=off" mode with IDE drive emulation
by removing the buffer used in the IDE emulation.
---
block.c | 10 +++
block.h |2
block_int.h |1
cpu-all.h |1
exec.c | 19 ++
hw/ide.c| 176 +---
vl.c|1
7 files changed, 204 insertions(+), 6 deletions(-)
Index: qemu/block.c
===
--- qemu.orig/block.c 2007-12-17 21:48:30.0 +0100
+++ qemu/block.c2007-12-17 22:21:23.0 +0100
@@ -758,6 +758,11 @@ void bdrv_set_translation_hint(BlockDriv
bs->translation = translation;
}
+void bdrv_set_cache_hint(BlockDriverState *bs, int cache)
+{
+bs->cache = cache;
+}
+
void bdrv_get_geometry_hint(BlockDriverState *bs,
int *pcyls, int *pheads, int *psecs)
{
@@ -786,6 +791,11 @@ int bdrv_is_read_only(BlockDriverState *
return bs->read_only;
}
+int bdrv_is_cached(BlockDriverState *bs)
+{
+return bs->cache;
+}
+
/* XXX: no longer used */
void bdrv_set_change_cb(BlockDriverState *bs,
void (*change_cb)(void *opaque), void *opaque)
Index: qemu/block.h
===
--- qemu.orig/block.h 2007-12-17 21:48:30.0 +0100
+++ qemu/block.h2007-12-17 22:21:23.0 +0100
@@ -113,6 +113,7 @@ void bdrv_set_geometry_hint(BlockDriverS
int cyls, int heads, int secs);
void bdrv_set_type_hint(BlockDriverState *bs, int type);
void bdrv_set_translation_hint(BlockDriverState *bs, int translation);
+void bdrv_set_cache_hint(BlockDriverState *bs, int cache);
void bdrv_get_geometry_hint(BlockDriverState *bs,
int *pcyls, int *pheads, int *psecs);
int bdrv_get_type_hint(BlockDriverState *bs);
@@ -120,6 +121,7 @@ int bdrv_get_translation_hint(BlockDrive
int bdrv_is_removable(BlockDriverState *bs);
int bdrv_is_read_only(BlockDriverState *bs);
int bdrv_is_inserted(BlockDriverState *bs);
+int bdrv_is_cached(BlockDriverState *bs);
int bdrv_media_changed(BlockDriverState *bs);
int bdrv_is_locked(BlockDriverState *bs);
void bdrv_set_locked(BlockDriverState *bs, int locked);
Index: qemu/block_int.h
===
--- qemu.orig/block_int.h 2007-12-17 21:39:22.0 +0100
+++ qemu/block_int.h2007-12-17 22:21:23.0 +0100
@@ -124,6 +124,7 @@ struct BlockDriverState {
drivers. They are not used by the block driver */
int cyls, heads, secs, translation;
int type;
+int cache;
char device_name[32];
BlockDriverState *next;
};
Index: qemu/cpu-all.h
===
--- qemu.orig/cpu-all.h 2007-12-13 09:19:28.0 +0100
+++ qemu/cpu-all.h 2007-12-17 22:21:23.0 +0100
@@ -838,6 +838,7 @@ int cpu_register_io_memory(int io_index,
CPUWriteMemoryFunc **cpu_get_io_memory_write(int io_index);
CPUReadMemoryFunc **cpu_get_io_memory_read(int io_index);
+extern uint8_t * cpu_physical_page_addr(target_phys_addr_t addr);
void cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf,
int len, int is_write);
static inline void cpu_physical_memory_read(target_phys_addr_t addr,
Index: qemu/exec.c
===
--- qemu.orig/exec.c2007-12-17 09:09:56.0 +0100
+++ qemu/exec.c 2007-12-17 22:21:23.0 +0100
@@ -2071,6 +2071,25 @@ void cpu_register_physical_memory(target
}
}
+uint8_t * cpu_physical_page_addr(target_phys_addr_t addr)
+{
+target_phys_addr_t page;
+unsigned long pd;
+PhysPageDesc *p;
+unsigned long addr1;
+
+page = addr & TARGET_PAGE_MASK;
+p = phys_page_find(page >> TARGET_PAGE_BITS);
+if (!p)
+ return (uint8_t*)-1;
+
+pd = p->phys_offset;
+
+addr1 = (pd & TARGET_PAGE_MASK) + (addr & ~TARGET_PAGE_MASK);
+
+return phys_ram_base + addr1;
+}
+
/* XXX: temporary until new memory mapping API */
uint32_t cpu_get_physical_page_desc(target_phys_addr_t addr)
{
Index: qemu/hw/ide.c
===
--- qemu.orig/hw/ide.c 2007-12-17 21:48:30.0 +0100
+++ qemu/hw/ide.c 2007-12-17 22:21:23.0 +0100
@@ -815,7 +815,7 @@ static int dma_buf_rw(BMDMAState *bm, in
}
/* XXX: handle errors */
-static void ide_read_dma_cb(void *opaque, int ret)
+static void ide_read_dma_cb_buffered(void *opaque, int ret)
{
BMDMAState *bm = opaque;
IDEState *s = bm->ide_if;
@@ -855,7 +855,86 @@ static void ide_read_dma_cb(void *opaque
printf("aio_read: sector_num=%lld n=%d\n", sector_num, n);
#endif
bm->aiocb = bdrv_aio_read(s->bs, sector_num, s->io_buffer, n,
- ide_read_dma_cb, bm);
+
