Re: [Qemu-devel] [PATCH 2/6] xen: add mapcache stubs

[Alexander Graf]

On 20.07.2011, at 18:41, Stefan Weil wrote:

> Am 19.07.2011 04:53, schrieb Alexander Graf:
>> During the transition to get rid of CONFIG_XEN_MAPCACHE we lost the mapcache
>> stubs along the way. Nobody realized it because the commands were guarded by
>> if (xen_enabled()) clauses that made gcc optimize out the respective calls.
>> 
>> This patch adds the stubs again - this time in the generic xen-stubs.c
>> 
>> Signed-off-by: Alexander Graf <address@hidden>
>> ---
>> xen-stub.c | 26 ++++++++++++++++++++++++++
>> 1 files changed, 26 insertions(+), 0 deletions(-)
>> 
>> diff --git a/xen-stub.c b/xen-stub.c
>> index efe2ab5..76d80e9 100644
>> --- a/xen-stub.c
>> +++ b/xen-stub.c
>> @@ -8,6 +8,7 @@
>> 
>> #include "qemu-common.h"
>> #include "hw/xen.h"
>> +#include "xen-mapcache.h"
>> 
>> void xenstore_store_pv_console_info(int i, CharDriverState *chr)
>> {
>> @@ -43,3 +44,28 @@ int xen_init(void)
>> {
>> return -ENOSYS;
>> }
>> +
>> +/******* mapcache stubs *******/
>> +
>> +void xen_map_cache_init(void)
>> +{
>> +}
>> +
>> +uint8_t *xen_map_cache(target_phys_addr_t phys_addr, target_phys_addr_t 
>> size,
>> + uint8_t lock)
>> +{
>> + return qemu_get_ram_ptr(phys_addr);
>> +}
>> +
>> +ram_addr_t xen_ram_addr_from_mapcache(void *ptr)
>> +{
>> + return -1;
>> +}
>> +
>> +void xen_invalidate_map_cache(void)
>> +{
>> +}
>> +
>> +void xen_invalidate_map_cache_entry(uint8_t *buffer)
>> +{
>> +}
> 
> The patch fixes a build problem, and the sooner we fix it,
> the better it is.
> 
> Do we really need a return value other than NULL in xen_map_cache()?
> Do we need the stubs for xen_map_cache_init() and xen_invalidate_map_cache()?
> As discussed in another thread, static inline stub function might be better.

I'm fairly sure we don't, but I merely shoved everything that was in 
xen-mapcache-stubs.c into xen-stubs.c. We can concentrate on optimizing this 
out again when the build works. If we really care about it.


Alex