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xen: mapcache performance improvements

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Use qemu_invalidate_entry in cpu_physical_memory_unmap.

Do not lock mapcache entries in qemu_get_ram_ptr if the address falls in
the ramblock with offset == 0. We don't need to do that because the
callers of qemu_get_ram_ptr either try to map an entire block, other
from the main ramblock, or until the end of a page to implement a single
read or write in the main ramblock.
If we don't lock mapcache entries in qemu_get_ram_ptr we don't need to
call qemu_invalidate_entry in qemu_put_ram_ptr anymore because we can
leave with few long lived block mappings requested by devices.

Also move the call to qemu_ram_addr_from_mapcache at the beginning of
qemu_ram_addr_from_host.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Stefano Stabellini 2011-05-19 18:35:46 +01:00 committed by Alexander Graf
parent 38bee5dc94
commit 712c2b4149
1 changed files with 10 additions and 18 deletions
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28
exec.c
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@ -3085,9 +3085,10 @@ void *qemu_get_ram_ptr(ram_addr_t addr)
if (xen_mapcache_enabled()) { if (xen_mapcache_enabled()) {
/* We need to check if the requested address is in the RAM /* We need to check if the requested address is in the RAM
* because we don't want to map the entire memory in QEMU. * because we don't want to map the entire memory in QEMU.
* In that case just map until the end of the page.
*/ */
if (block->offset == 0) { if (block->offset == 0) {
return qemu_map_cache(addr, 0, 1); return qemu_map_cache(addr, 0, 0);
} else if (block->host == NULL) { } else if (block->host == NULL) {
block->host = qemu_map_cache(block->offset, block->length, 1); block->host = qemu_map_cache(block->offset, block->length, 1);
} }
@ -3114,9 +3115,10 @@ void *qemu_safe_ram_ptr(ram_addr_t addr)
if (xen_mapcache_enabled()) { if (xen_mapcache_enabled()) {
/* We need to check if the requested address is in the RAM /* We need to check if the requested address is in the RAM
* because we don't want to map the entire memory in QEMU. * because we don't want to map the entire memory in QEMU.
* In that case just map until the end of the page.
*/ */
if (block->offset == 0) { if (block->offset == 0) {
return qemu_map_cache(addr, 0, 1); return qemu_map_cache(addr, 0, 0);
} else if (block->host == NULL) { } else if (block->host == NULL) {
block->host = qemu_map_cache(block->offset, block->length, 1); block->host = qemu_map_cache(block->offset, block->length, 1);
} }
@ -3159,10 +3161,6 @@ void *qemu_ram_ptr_length(target_phys_addr_t addr, target_phys_addr_t *size)
void qemu_put_ram_ptr(void *addr) void qemu_put_ram_ptr(void *addr)
{ {
trace_qemu_put_ram_ptr(addr); trace_qemu_put_ram_ptr(addr);
if (xen_mapcache_enabled()) {
qemu_invalidate_entry(block->host);
}
} }
int qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr) int qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr)
@ -3170,6 +3168,11 @@ int qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr)
RAMBlock *block; RAMBlock *block;
uint8_t *host = ptr; uint8_t *host = ptr;
if (xen_mapcache_enabled()) {
*ram_addr = qemu_ram_addr_from_mapcache(ptr);
return 0;
}
QLIST_FOREACH(block, &ram_list.blocks, next) { QLIST_FOREACH(block, &ram_list.blocks, next) {
/* This case append when the block is not mapped. */ /* This case append when the block is not mapped. */
if (block->host == NULL) { if (block->host == NULL) {
@ -3181,11 +3184,6 @@ int qemu_ram_addr_from_host(void *ptr, ram_addr_t *ram_addr)
} }
} }
if (xen_mapcache_enabled()) {
*ram_addr = qemu_ram_addr_from_mapcache(ptr);
return 0;
}
return -1; return -1;
} }
@ -4086,13 +4084,7 @@ void cpu_physical_memory_unmap(void *buffer, target_phys_addr_t len,
} }
} }
if (xen_mapcache_enabled()) { if (xen_mapcache_enabled()) {
uint8_t *buffer1 = buffer; qemu_invalidate_entry(buffer);
uint8_t *end_buffer = buffer + len;
while (buffer1 < end_buffer) {
qemu_put_ram_ptr(buffer1);
buffer1 += TARGET_PAGE_SIZE;
}
} }
return; return;
} }