* Re: [PATCH][TOOLS] libxc: mmap fixes for BSD
2008-06-10 14:21 ` Keir Fraser
2008-06-10 14:37 ` Christoph Egger
@ 2008-07-23 15:11 ` Christoph Egger
1 sibling, 0 replies; 4+ messages in thread
From: Christoph Egger @ 2008-07-23 15:11 UTC (permalink / raw)
To: Keir Fraser; +Cc: xen-devel
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On Tuesday 10 June 2008 16:21:56 Keir Fraser wrote:
> On 10/6/08 15:09, "Christoph Egger" <Christoph.Egger@amd.com> wrote:
> > On BSD, mmap()ing files works on on-disk files but not on
> > pseudo filesystems like kernfs or procfs.
> > Therefore, attached patch mmap()s anonymous memory.
> >
> > Linux equivalents are sysfs and procfs to above BSD's pseudo-filesystems.
> > On Linux, mmap is implemented for sysfs but it is questionable to me
> > how write operations work since (most) files in sysfs have
> > static content. So this patch may fix some problems
> > with a Linux Dom0, too.
>
> We can hide special setup in mmap(/proc/xen/privcmd) that is necessary for
> later foreign mapping operations. Perhaps xc_map_foreign_ranges() interface
> could be changed so that it does the mmap(), then fills in the .va field in
> the array of entries that it is passed, and finally return the address it
> got from mmap()?
>
> This would make xc_map_foreign_ranges() similar to our other xc_map*()
> functions, which all hide the mmap() invocation inside their
> implementation.
>
> -- Keir
Here is the patch. This also cleans up and fixes memory leaks in the
error path.
Christoph
--
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Operating System Research Center
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diff -r f86941c1b523 tools/libxc/xc_dom_boot.c
--- a/tools/libxc/xc_dom_boot.c Tue Jul 22 16:03:45 2008 +0100
+++ b/tools/libxc/xc_dom_boot.c Wed Jul 23 16:55:27 2008 +0200
@@ -153,7 +153,7 @@ void *xc_dom_boot_domU_map(struct xc_dom
int page_shift = XC_DOM_PAGE_SHIFT(dom);
privcmd_mmap_entry_t *entries;
void *ptr;
- int i, rc;
+ int i;
int err;
entries = xc_dom_malloc(dom, count * sizeof(privcmd_mmap_entry_t));
@@ -165,9 +165,13 @@ void *xc_dom_boot_domU_map(struct xc_dom
return NULL;
}
- ptr = mmap(NULL, count << page_shift, PROT_READ | PROT_WRITE,
- MAP_SHARED, dom->guest_xc, 0);
- if ( ptr == MAP_FAILED )
+ for ( i = 0; i < count; i++ )
+ entries[i].mfn = xc_dom_p2m_host(dom, pfn + i);
+
+ ptr = xc_map_foreign_ranges(dom->guest_xc, dom->guest_domid,
+ count << page_shift, PROT_READ | PROT_WRITE, 1 << page_shift,
+ entries, count);
+ if ( ptr == NULL )
{
err = errno;
xc_dom_panic(XC_INTERNAL_ERROR,
@@ -177,22 +181,6 @@ void *xc_dom_boot_domU_map(struct xc_dom
return NULL;
}
- for ( i = 0; i < count; i++ )
- {
- entries[i].va = (uintptr_t) ptr + (i << page_shift);
- entries[i].mfn = xc_dom_p2m_host(dom, pfn + i);
- entries[i].npages = 1;
- }
-
- rc = xc_map_foreign_ranges(dom->guest_xc, dom->guest_domid,
- entries, count);
- if ( rc < 0 )
- {
- xc_dom_panic(XC_INTERNAL_ERROR,
- "%s: failed to mmap domU pages 0x%" PRIpfn "+0x%" PRIpfn
- " [xenctl, rc=%d]\n", __FUNCTION__, pfn, count, rc);
- return NULL;
- }
return ptr;
}
diff -r f86941c1b523 tools/libxc/xc_domain_save.c
--- a/tools/libxc/xc_domain_save.c Tue Jul 22 16:03:45 2008 +0100
+++ b/tools/libxc/xc_domain_save.c Wed Jul 23 16:55:27 2008 +0200
@@ -568,16 +568,19 @@ static xen_pfn_t *xc_map_m2p(int xc_hand
unsigned long m2p_chunks, m2p_size;
xen_pfn_t *m2p;
xen_pfn_t *extent_start;
- int i, rc;
+ int i;
+ m2p = NULL;
m2p_size = M2P_SIZE(max_mfn);
m2p_chunks = M2P_CHUNKS(max_mfn);
xmml.max_extents = m2p_chunks;
- if ( !(extent_start = malloc(m2p_chunks * sizeof(xen_pfn_t))) )
+
+ extent_start = calloc(m2p_chunks, sizeof(xen_pfn_t));
+ if ( !extent_start )
{
ERROR("failed to allocate space for m2p mfns");
- return NULL;
+ goto err0;
}
set_xen_guest_handle(xmml.extent_start, extent_start);
@@ -585,41 +588,36 @@ static xen_pfn_t *xc_map_m2p(int xc_hand
(xmml.nr_extents != m2p_chunks) )
{
ERROR("xc_get_m2p_mfns");
- return NULL;
+ goto err1;
}
- if ( (m2p = mmap(NULL, m2p_size, prot,
- MAP_SHARED, xc_handle, 0)) == MAP_FAILED )
- {
- ERROR("failed to mmap m2p");
- return NULL;
- }
-
- if ( !(entries = malloc(m2p_chunks * sizeof(privcmd_mmap_entry_t))) )
+ entries = calloc(m2p_chunks, sizeof(privcmd_mmap_entry_t));
+ if (entries == NULL)
{
ERROR("failed to allocate space for mmap entries");
- return NULL;
+ goto err1;
}
for ( i = 0; i < m2p_chunks; i++ )
+ entries[i].mfn = extent_start[i];
+
+ m2p = xc_map_foreign_ranges(xc_handle, DOMID_XEN,
+ m2p_size, prot, M2P_CHUNK_SIZE,
+ entries, m2p_chunks);
+ if (m2p == NULL)
{
- entries[i].va = (unsigned long)(((void *)m2p) + (i * M2P_CHUNK_SIZE));
- entries[i].mfn = extent_start[i];
- entries[i].npages = M2P_CHUNK_SIZE >> PAGE_SHIFT;
- }
-
- if ( (rc = xc_map_foreign_ranges(xc_handle, DOMID_XEN,
- entries, m2p_chunks)) < 0 )
- {
- ERROR("xc_mmap_foreign_ranges failed (rc = %d)", rc);
- return NULL;
+ ERROR("xc_mmap_foreign_ranges failed");
+ goto err2;
}
m2p_mfn0 = entries[0].mfn;
+err2:
+ free(entries);
+err1:
free(extent_start);
- free(entries);
+err0:
return m2p;
}
diff -r f86941c1b523 tools/libxc/xc_hvm_build.c
--- a/tools/libxc/xc_hvm_build.c Tue Jul 22 16:03:45 2008 +0100
+++ b/tools/libxc/xc_hvm_build.c Wed Jul 23 16:55:27 2008 +0200
@@ -115,27 +115,21 @@ static int loadelfimage(
struct elf_binary *elf, int xch, uint32_t dom, unsigned long *parray)
{
privcmd_mmap_entry_t *entries = NULL;
- int pages = (elf->pend - elf->pstart + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ size_t pages = (elf->pend - elf->pstart + PAGE_SIZE - 1) >> PAGE_SHIFT;
int i, rc = -1;
/* Map address space for initial elf image. */
- entries = malloc(pages * sizeof(privcmd_mmap_entry_t));
+ entries = calloc(pages, sizeof(privcmd_mmap_entry_t));
if ( entries == NULL )
- goto err;
- elf->dest = mmap(NULL, pages << PAGE_SHIFT, PROT_READ | PROT_WRITE,
- MAP_SHARED, xch, 0);
- if ( elf->dest == MAP_FAILED )
goto err;
for ( i = 0; i < pages; i++ )
- {
- entries[i].va = (uintptr_t)elf->dest + (i << PAGE_SHIFT);
entries[i].mfn = parray[(elf->pstart >> PAGE_SHIFT) + i];
- entries[i].npages = 1;
- }
- rc = xc_map_foreign_ranges(xch, dom, entries, pages);
- if ( rc < 0 )
+ elf->dest = xc_map_foreign_ranges(xch, dom, pages << PAGE_SHIFT,
+ PROT_READ | PROT_WRITE, 1 << PAGE_SHIFT,
+ entries, pages);
+ if (elf->dest == NULL)
goto err;
/* Load the initial elf image. */
@@ -143,12 +137,6 @@ static int loadelfimage(
rc = 0;
err:
- if ( elf->dest )
- {
- munmap(elf->dest, pages << PAGE_SHIFT);
- elf->dest = NULL;
- }
-
if ( entries )
free(entries);
diff -r f86941c1b523 tools/libxc/xc_linux.c
--- a/tools/libxc/xc_linux.c Tue Jul 22 16:03:45 2008 +0100
+++ b/tools/libxc/xc_linux.c Wed Jul 23 16:55:27 2008 +0200
@@ -118,16 +118,41 @@ void *xc_map_foreign_range(int xc_handle
return addr;
}
-int xc_map_foreign_ranges(int xc_handle, uint32_t dom,
- privcmd_mmap_entry_t *entries, int nr)
+void *xc_map_foreign_ranges(int xc_handle, uint32_t dom,
+ size_t size, int prot, size_t chunksize,
+ privcmd_mmap_entry_t entries[], int nentries)
{
privcmd_mmap_t ioctlx;
- ioctlx.num = nr;
+ int i, rc;
+ void *addr;
+
+ addr = mmap(NULL, size, prot, MAP_SHARED, xc_handle, 0);
+ if (addr == MAP_FAILED)
+ goto mmap_failed;
+
+ for (i = 0; i < nentries; i++) {
+ entries[i].va = (uintptr_t)addr + (i * chunksize);
+ entries[i].npages = chunksize >> PAGE_SHIFT;
+ }
+
+ ioctlx.num = nentries;
ioctlx.dom = dom;
ioctlx.entry = entries;
- return ioctl(xc_handle, IOCTL_PRIVCMD_MMAP, &ioctlx);
+ rc = ioctl(xc_handle, IOCTL_PRIVCMD_MMAP, &ioctlx);
+ if (rc)
+ goto ioctl_failed;
+
+ return addr;
+
+ioctl_failed:
+ rc = munmap(addr, size);
+ if (rc == -1)
+ ERROR("%s: error in error path\n", __FUNCTION__);
+
+mmap_failed:
+ return NULL;
}
static int do_privcmd(int xc_handle, unsigned int cmd, unsigned long data)
diff -r f86941c1b523 tools/libxc/xc_minios.c
--- a/tools/libxc/xc_minios.c Tue Jul 22 16:03:45 2008 +0100
+++ b/tools/libxc/xc_minios.c Wed Jul 23 16:55:27 2008 +0200
@@ -76,6 +76,16 @@ void *xc_map_foreign_range(int xc_handle
return map_frames_ex(&mfn, size / getpagesize(), 0, 1, 1, dom, 0, pt_prot);
}
+void *xc_map_foreign_ranges(int xc_handle, uint32_t dom,
+ size_t size, int prot, size_t chunksize,
+ privcmd_mmap_entry_t entries[], int nentries)
+{
+ ERROR("%s: implement me\n");
+ return NULL;
+}
+
+
+#if 0
int xc_map_foreign_ranges(int xc_handle, uint32_t dom,
privcmd_mmap_entry_t *entries, int nr)
{
@@ -86,6 +96,7 @@ int xc_map_foreign_ranges(int xc_handle,
}
return 0;
}
+#endif
int do_xen_hypercall(int xc_handle, privcmd_hypercall_t *hypercall)
{
diff -r f86941c1b523 tools/libxc/xc_netbsd.c
--- a/tools/libxc/xc_netbsd.c Tue Jul 22 16:03:45 2008 +0100
+++ b/tools/libxc/xc_netbsd.c Wed Jul 23 16:55:27 2008 +0200
@@ -11,7 +11,6 @@
#include "xc_private.h"
-#include <xen/memory.h>
#include <xen/sys/evtchn.h>
#include <unistd.h>
#include <fcntl.h>
@@ -114,22 +113,42 @@ void *xc_map_foreign_range(int xc_handle
return addr;
}
-int xc_map_foreign_ranges(int xc_handle, uint32_t dom,
- privcmd_mmap_entry_t *entries, int nr)
+void *xc_map_foreign_ranges(int xc_handle, uint32_t dom,
+ size_t size, int prot, size_t chunksize,
+ privcmd_mmap_entry_t entries[], int nentries)
{
- privcmd_mmap_t ioctlx;
- int err;
+ privcmd_mmap_t ioctlx;
+ int i, rc;
+ void *addr;
- ioctlx.num = nr;
- ioctlx.dom = dom;
- ioctlx.entry = entries;
+ addr = mmap(NULL, size, prot, MAP_ANON | MAP_SHARED, -1, 0);
+ if (addr == MAP_FAILED)
+ goto mmap_failed;
- err = ioctl(xc_handle, IOCTL_PRIVCMD_MMAP, &ioctlx);
- if (err == 0)
- return 0;
- else
- return -errno;
+ for (i = 0; i < nentries; i++) {
+ entries[i].va = (uintptr_t)addr + (i * chunksize);
+ entries[i].npages = chunksize >> PAGE_SHIFT;
+ }
+
+ ioctlx.num = nentries;
+ ioctlx.dom = dom;
+ ioctlx.entry = entries;
+
+ rc = ioctl(xc_handle, IOCTL_PRIVCMD_MMAP, &ioctlx);
+ if (rc)
+ goto ioctl_failed;
+
+ return addr;
+
+ioctl_failed:
+ rc = munmap(addr, size);
+ if (rc == -1)
+ ERROR("%s: error in error path\n", __FUNCTION__);
+
+mmap_failed:
+ return NULL;
}
+
static int do_privcmd(int xc_handle, unsigned int cmd, unsigned long data)
{
diff -r f86941c1b523 tools/libxc/xc_private.h
--- a/tools/libxc/xc_private.h Tue Jul 22 16:03:45 2008 +0100
+++ b/tools/libxc/xc_private.h Wed Jul 23 16:55:27 2008 +0200
@@ -184,8 +184,9 @@ static inline int do_sysctl(int xc_handl
return ret;
}
-int xc_map_foreign_ranges(int xc_handle, uint32_t dom,
- privcmd_mmap_entry_t *entries, int nr);
+void *xc_map_foreign_ranges(int xc_handle, uint32_t dom,
+ size_t size, int prot, size_t chunksize,
+ privcmd_mmap_entry_t entries[], int nentries);
void *map_domain_va_core(unsigned long domfd, int cpu, void *guest_va,
vcpu_guest_context_any_t *ctxt);
diff -r f86941c1b523 tools/libxc/xc_solaris.c
--- a/tools/libxc/xc_solaris.c Tue Jul 22 16:03:45 2008 +0100
+++ b/tools/libxc/xc_solaris.c Wed Jul 23 16:55:27 2008 +0200
@@ -109,17 +109,40 @@ void *xc_map_foreign_range(int xc_handle
return addr;
}
-int xc_map_foreign_ranges(int xc_handle, uint32_t dom,
- privcmd_mmap_entry_t *entries, int nr)
+void *xc_map_foreign_ranges(int xc_handle, uint32_t dom,
+ size_t size, int prot, size_t chunksize,
+ privcmd_mmap_entry_t entries[], int nentries)
{
privcmd_mmap_t ioctlx;
+ int i, rc;
+ void *addr;
- ioctlx.num = nr;
+ addr = mmap(NULL, size, prot, MAP_SHARED, xc_handle, 0);
+ if (addr == MAP_FAILED)
+ goto mmap_failed;
+
+ for (i = 0; i < nentries; i++) {
+ entries[i].va = (uintptr_t)addr + (i * chunksize);
+ entries[i].npages = chunksize >> PAGE_SHIFT;
+ }
+
+ ioctlx.num = nentries;
ioctlx.dom = dom;
ioctlx.entry = entries;
- return ioctl(xc_handle, IOCTL_PRIVCMD_MMAP, &ioctlx);
+ rc = ioctl(xc_handle, IOCTL_PRIVCMD_MMAP, &ioctlx);
+ if (rc)
+ goto ioctl_failed;
+
+ioctl_failed:
+ rc = munmap(addr, size);
+ if (rc == -1)
+ ERROR("%s: error in error path\n", __FUNCTION__);
+
+mmap_failed:
+ return NULL;
}
+
static int do_privcmd(int xc_handle, unsigned int cmd, unsigned long data)
{
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