Re: [Qemu-devel] [PATCH] xen: Use conditional compilation for xen map cache (fixes w32 builds)

[Stefano Stabellini]

On Wed, 18 May 2011, Stefan Weil wrote:
> The current implementation used stubs for systems without XEN.
> This is unusual for QEMU and adds unneeded dependencies.
> 
> MinGW32 for example does not provide munmap(), so the XEN
> code creates compiler warnings (missing prototype).
> Compilations without optimisation even result in linker
> errors (missing function).
> 
> Fix this by using conditional compilation.

After a conversation on IRC with Stefan I found out that most of the
problems are gone away after my recent "xen mapcache fixes and
improvements" patch series.

To completely solve the compilation issues with MinGW32 I just need to
remove two includes from xen-mapcache.h, so I am appending an updated
version of patch #3 "xen: remove xen_map_block and xen_unmap_block" to
do just that.

I have also pushed another git branch:

git://xenbits.xen.org/people/sstabellini/qemu-dm.git mapcache_fixes_2

---


commit 8e1040ee219513d2c692f921f80e2d850aaa47c7
Author: Stefano Stabellini <address@hidden>
Date:   Fri May 13 11:58:59 2011 +0000

    xen: remove xen_map_block and xen_unmap_block
    
    Replace xen_map_block with qemu_map_cache with the appropriate locking
    and size parameters.
    Replace xen_unmap_block with qemu_invalidate_entry.
    
    Signed-off-by: Stefano Stabellini <address@hidden>

diff --git a/exec.c b/exec.c
index 01498d2..21f21f0 100644
--- a/exec.c
+++ b/exec.c
@@ -54,6 +54,7 @@
 #endif
 #else /* !CONFIG_USER_ONLY */
 #include "xen-mapcache.h"
+#include "trace.h"
 #endif
 
 //#define DEBUG_TB_INVALIDATE
@@ -3068,7 +3069,7 @@ void *qemu_get_ram_ptr(ram_addr_t addr)
                 if (block->offset == 0) {
                     return qemu_map_cache(addr, 0, 1);
                 } else if (block->host == NULL) {
-                    block->host = xen_map_block(block->offset, block->length);
+                    block->host = qemu_map_cache(block->offset, block->length, 
1);
                 }
             }
             return block->host + (addr - block->offset);
@@ -3097,7 +3098,7 @@ void *qemu_safe_ram_ptr(ram_addr_t addr)
                 if (block->offset == 0) {
                     return qemu_map_cache(addr, 0, 1);
                 } else if (block->host == NULL) {
-                    block->host = xen_map_block(block->offset, block->length);
+                    block->host = qemu_map_cache(block->offset, block->length, 
1);
                 }
             }
             return block->host + (addr - block->offset);
@@ -3115,19 +3116,7 @@ void qemu_put_ram_ptr(void *addr)
     trace_qemu_put_ram_ptr(addr);
 
     if (xen_mapcache_enabled()) {
-        RAMBlock *block;
-
-        QLIST_FOREACH(block, &ram_list.blocks, next) {
-            if (addr == block->host) {
-                break;
-            }
-        }
-        if (block && block->host) {
-            xen_unmap_block(block->host, block->length);
-            block->host = NULL;
-        } else {
-            qemu_invalidate_entry(addr);
-        }
+            qemu_invalidate_entry(block->host);
     }
 }
 
diff --git a/xen-mapcache-stub.c b/xen-mapcache-stub.c
index 60f712b..8a2380a 100644
--- a/xen-mapcache-stub.c
+++ b/xen-mapcache-stub.c
@@ -34,7 +34,3 @@ void qemu_invalidate_map_cache(void)
 void qemu_invalidate_entry(uint8_t *buffer)
 {
 }
-uint8_t *xen_map_block(target_phys_addr_t phys_addr, target_phys_addr_t size)
-{
-    return NULL;
-}
diff --git a/xen-mapcache.c b/xen-mapcache.c
index 57fe24d..fac47cd 100644
--- a/xen-mapcache.c
+++ b/xen-mapcache.c
@@ -362,34 +362,3 @@ void qemu_invalidate_map_cache(void)
 
     mapcache_unlock();
 }
-
-uint8_t *xen_map_block(target_phys_addr_t phys_addr, target_phys_addr_t size)
-{
-    uint8_t *vaddr_base;
-    xen_pfn_t *pfns;
-    int *err;
-    unsigned int i;
-    target_phys_addr_t nb_pfn = size >> XC_PAGE_SHIFT;
-
-    trace_xen_map_block(phys_addr, size);
-    phys_addr >>= XC_PAGE_SHIFT;
-
-    pfns = qemu_mallocz(nb_pfn * sizeof (xen_pfn_t));
-    err = qemu_mallocz(nb_pfn * sizeof (int));
-
-    for (i = 0; i < nb_pfn; i++) {
-        pfns[i] = phys_addr + i;
-    }
-
-    vaddr_base = xc_map_foreign_bulk(xen_xc, xen_domid, PROT_READ|PROT_WRITE,
-                                     pfns, err, nb_pfn);
-    if (vaddr_base == NULL) {
-        perror("xc_map_foreign_bulk");
-        exit(-1);
-    }
-
-    qemu_free(pfns);
-    qemu_free(err);
-
-    return vaddr_base;
-}
diff --git a/xen-mapcache.h b/xen-mapcache.h
index b89b8f9..6216cc3 100644
--- a/xen-mapcache.h
+++ b/xen-mapcache.h
@@ -9,27 +9,12 @@
 #ifndef XEN_MAPCACHE_H
 #define XEN_MAPCACHE_H
 
-#include <sys/mman.h>
-#include "trace.h"
-
 void     qemu_map_cache_init(void);
 uint8_t  *qemu_map_cache(target_phys_addr_t phys_addr, target_phys_addr_t 
size, uint8_t lock);
 ram_addr_t qemu_ram_addr_from_mapcache(void *ptr);
 void     qemu_invalidate_entry(uint8_t *buffer);
 void     qemu_invalidate_map_cache(void);
 
-uint8_t *xen_map_block(target_phys_addr_t phys_addr, target_phys_addr_t size);
-
-static inline void xen_unmap_block(void *addr, ram_addr_t size)
-{
-    trace_xen_unmap_block(addr, size);
-
-    if (munmap(addr, size) != 0) {
-        hw_error("xen_unmap_block: %s", strerror(errno));
-    }
-}
-
-
 #define mapcache_lock()   ((void)0)
 #define mapcache_unlock() ((void)0)