Re: Remove qemu_alloc_physram()

[Avi Kivity <avi@redhat.com>]

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nicolas prochazka wrote:
> Hello,
> Since this patch :
> http://git.kernel.org/?p=virt/kvm/qemu-kvm.git;a=commit;h=0e8d16ba06486ebf79f131f28121774715975248
> Remove qemu_alloc_physram()
> Obsolete.
>
> function alloc_mem_area(memory, &map_len, mem_path);  is never calling in code,
> and it seems that's  -mem-path ( or -mempath) /hugepages  does not
> work for me now.
> before this patch, i can see for example in /proc/meminfo :
> HugePages_Total:  2560
> HugePages_Free:   2301
> when i start one kvm/qemu
>
> now , HupePages_Free never down , hugepages_free = hugepages_total.
>
>   

Please test the attached patch.

-- 
error compiling committee.c: too many arguments to function


[-- Attachment #2: mem-path.patch --]
[-- Type: text/x-patch, Size: 6362 bytes --]

diff --git a/exec.c b/exec.c
index e241f05..c024b8b 100644
--- a/exec.c
+++ b/exec.c
@@ -2484,6 +2484,113 @@ static ram_addr_t kqemu_ram_alloc(ram_addr_t size)
 }
 #endif
 
+#ifdef __linux__
+
+#include <sys/vfs.h>
+
+#define HUGETLBFS_MAGIC       0x958458f6
+
+static long gethugepagesize(const char *path)
+{
+    struct statfs fs;
+    int ret;
+
+    do {
+	    ret = statfs(path, &fs);
+    } while (ret != 0 && errno == EINTR);
+
+    if (ret != 0) {
+	    perror("statfs");
+	    return 0;
+    }
+
+    if (fs.f_type != HUGETLBFS_MAGIC)
+	    fprintf(stderr, "Warning: path not on HugeTLBFS: %s\n", path);
+
+    return fs.f_bsize;
+}
+
+static void *file_ram_alloc(ram_addr_t memory, const char *path)
+{
+    char *filename;
+    void *area;
+    int fd;
+#ifdef MAP_POPULATE
+    int flags;
+#endif
+    unsigned long hpagesize;
+    extern int mem_prealloc;
+
+    if (!path) {
+        return NULL;
+    }
+
+    hpagesize = gethugepagesize(path);
+    if (!hpagesize) {
+	return NULL;
+    }
+
+    if (memory < hpagesize) {
+        return NULL;
+    }
+
+    if (kvm_enabled() && !kvm_has_sync_mmu()) {
+        fprintf(stderr, "host lacks mmu notifiers, disabling --mem-path\n");
+        return NULL;
+    }
+
+    if (asprintf(&filename, "%s/kvm.XXXXXX", path) == -1) {
+	return NULL;
+    }
+
+    fd = mkstemp(filename);
+    if (fd < 0) {
+	perror("mkstemp");
+	free(filename);
+	return NULL;
+    }
+    unlink(filename);
+    free(filename);
+
+    memory = (memory+hpagesize-1) & ~(hpagesize-1);
+
+    /*
+     * ftruncate is not supported by hugetlbfs in older
+     * hosts, so don't bother checking for errors.
+     * If anything goes wrong with it under other filesystems,
+     * mmap will fail.
+     */
+    ftruncate(fd, memory);
+
+#ifdef MAP_POPULATE
+    /* NB: MAP_POPULATE won't exhaustively alloc all phys pages in the case
+     * MAP_PRIVATE is requested.  For mem_prealloc we mmap as MAP_SHARED
+     * to sidestep this quirk.
+     */
+    flags = mem_prealloc ? MAP_POPULATE|MAP_SHARED : MAP_PRIVATE;
+    area = mmap(0, memory, PROT_READ|PROT_WRITE, flags, fd, 0);
+#else
+    area = mmap(0, memory, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
+#endif
+    if (area == MAP_FAILED) {
+	perror("alloc_mem_area: can't mmap hugetlbfs pages");
+	close(fd);
+	return (NULL);
+    }
+    return area;
+}
+
+#else
+
+static void *file_ram_alloc(ram_addr_t memory, const char *path)
+{
+    return NULL;
+}
+
+#endif
+
+extern const char *mem_path;
+
 ram_addr_t qemu_ram_alloc(ram_addr_t size)
 {
     RAMBlock *new_block;
@@ -2497,7 +2604,10 @@ ram_addr_t qemu_ram_alloc(ram_addr_t size)
     size = TARGET_PAGE_ALIGN(size);
     new_block = qemu_malloc(sizeof(*new_block));
 
-    new_block->host = qemu_vmalloc(size);
+    new_block->host = file_ram_alloc(size, mem_path);
+    if (!new_block->host) {
+        new_block->host = qemu_vmalloc(size);
+    }
     new_block->offset = last_ram_offset;
     new_block->length = size;
 
diff --git a/hw/pc.c b/hw/pc.c
index 9e99b7c..585a4ef 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -914,14 +914,6 @@ static void pc_init1(ram_addr_t ram_size,
         hw_error("To much RAM for 32-bit physical address");
 #else
         ram_addr = qemu_ram_alloc(above_4g_mem_size);
-        if (hpagesize) {
-            if (ram_addr & (hpagesize-1)) {
-                unsigned long aligned_addr;
-                aligned_addr = (ram_addr + hpagesize - 1) & ~(hpagesize-1);
-                qemu_ram_alloc(aligned_addr - ram_addr);
-                ram_addr = aligned_addr;
-            }
-        }
         cpu_register_physical_memory(0x100000000ULL,
                                      above_4g_mem_size,
                                      ram_addr);
diff --git a/vl.c b/vl.c
index db8265b..8aea7d6 100644
--- a/vl.c
+++ b/vl.c
@@ -41,7 +41,6 @@
 #include <sys/ioctl.h>
 #include <sys/resource.h>
 #include <sys/socket.h>
-#include <sys/vfs.h>
 #include <netinet/in.h>
 #include <net/if.h>
 #if defined(__NetBSD__)
@@ -268,7 +267,6 @@ const char *mem_path = NULL;
 #ifdef MAP_POPULATE
 int mem_prealloc = 1;	/* force preallocation of physical target memory */
 #endif
-long hpagesize = 0;
 #ifdef TARGET_ARM
 int old_param = 0;
 #endif
@@ -4856,90 +4854,6 @@ int qemu_uuid_parse(const char *str, uint8_t *uuid)
 
 #define MAX_NET_CLIENTS 32
 
-#ifdef USE_KVM
-
-#define HUGETLBFS_MAGIC       0x958458f6
-
-static long gethugepagesize(const char *path)
-{
-    struct statfs fs;
-    int ret;
-
-    do {
-	    ret = statfs(path, &fs);
-    } while (ret != 0 && errno == EINTR);
-
-    if (ret != 0) {
-	    perror("statfs");
-	    return 0;
-    }
-
-    if (fs.f_type != HUGETLBFS_MAGIC)
-	    fprintf(stderr, "Warning: path not on HugeTLBFS: %s\n", path);
-
-    return fs.f_bsize;
-}
-
-static void *alloc_mem_area(size_t memory, unsigned long *len, const char *path)
-{
-    char *filename;
-    void *area;
-    int fd;
-#ifdef MAP_POPULATE
-    int flags;
-#endif
-
-    if (!kvm_has_sync_mmu()) {
-        fprintf(stderr, "host lacks mmu notifiers, disabling --mem-path\n");
-        return NULL;
-    }
-
-    if (asprintf(&filename, "%s/kvm.XXXXXX", path) == -1)
-	return NULL;
-
-    hpagesize = gethugepagesize(path);
-    if (!hpagesize)
-	return NULL;
-
-    fd = mkstemp(filename);
-    if (fd < 0) {
-	perror("mkstemp");
-	free(filename);
-	return NULL;
-    }
-    unlink(filename);
-    free(filename);
-
-    memory = (memory+hpagesize-1) & ~(hpagesize-1);
-
-    /*
-     * ftruncate is not supported by hugetlbfs in older
-     * hosts, so don't bother checking for errors.
-     * If anything goes wrong with it under other filesystems,
-     * mmap will fail.
-     */
-    ftruncate(fd, memory);
-
-#ifdef MAP_POPULATE
-    /* NB: MAP_POPULATE won't exhaustively alloc all phys pages in the case
-     * MAP_PRIVATE is requested.  For mem_prealloc we mmap as MAP_SHARED
-     * to sidestep this quirk.
-     */
-    flags = mem_prealloc ? MAP_POPULATE|MAP_SHARED : MAP_PRIVATE;
-    area = mmap(0, memory, PROT_READ|PROT_WRITE, flags, fd, 0);
-#else
-    area = mmap(0, memory, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
-#endif
-    if (area == MAP_FAILED) {
-	perror("alloc_mem_area: can't mmap hugetlbfs pages");
-	close(fd);
-	return (NULL);
-    }
-    *len = memory;
-    return area;
-}
-#endif
-
 #ifndef _WIN32
 
 static void termsig_handler(int signal)