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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH] xen: arm: force guest memory accesses to cacheable when MMU is disabled
On Tue, 2014-01-07 at 16:02 +0000, Ian Campbell wrote:
> One thing I'm not sure about is reverting the previous fix in
> a0035ecc0d82.
> It's reasonably recent so reverting it takes us back to a pretty well
> understood state in the libraries. The functionality is harmless if
> incomplete. I think given the first argument I would lean towards
> reverting.
If the answer here is "revert" then that would be the following. I'd
probably rewrite "A previous patch" into a reference to the actual
applied patch as I committed it.
-------
From b33eb6a3d5082d3497b8ef0872c0bbd89fb74af1 Mon Sep 17 00:00:00 2001
From: Ian Campbell <ian.campbell@xxxxxxxxxx>
Date: Tue, 7 Jan 2014 15:52:29 +0000
Subject: [PATCH] Revert "tools: libxc: flush data cache after loading images
into guest memory"
This reverts commit a0035ecc0d82c1d4dcd5e429e2fcc3192d89747a.
Even with this fix there is a period between the flush and the unmap where
processor may speculate data into the cache. The solution is to map this
region uncached or to use the HCR.DC bit to mark all guest accesses cached. A
previous patch has arranged to do the latter.
Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
tools/libxc/xc_dom_armzimageloader.c | 1 -
tools/libxc/xc_dom_binloader.c | 1 -
tools/libxc/xc_dom_core.c | 2 --
tools/libxc/xc_linux_osdep.c | 41 ----------------------------------
tools/libxc/xc_minios.c | 12 ----------
tools/libxc/xc_netbsd.c | 14 ------------
tools/libxc/xc_private.c | 5 -----
tools/libxc/xc_private.h | 3 ---
tools/libxc/xc_solaris.c | 14 ------------
tools/libxc/xenctrl_osdep_ENOSYS.c | 9 --------
tools/libxc/xenctrlosdep.h | 1 -
11 files changed, 103 deletions(-)
diff --git a/tools/libxc/xc_dom_armzimageloader.c
b/tools/libxc/xc_dom_armzimageloader.c
index 508f74b..e6516a1 100644
--- a/tools/libxc/xc_dom_armzimageloader.c
+++ b/tools/libxc/xc_dom_armzimageloader.c
@@ -229,7 +229,6 @@ static int xc_dom_load_zimage_kernel(struct xc_dom_image
*dom)
__func__, dom->kernel_size, dom->kernel_blob, dst);
memcpy(dst, dom->kernel_blob, dom->kernel_size);
- xc_cache_flush(dom->xch, dst, dom->kernel_size);
return 0;
}
diff --git a/tools/libxc/xc_dom_binloader.c b/tools/libxc/xc_dom_binloader.c
index aa0463c..e1de5b5 100644
--- a/tools/libxc/xc_dom_binloader.c
+++ b/tools/libxc/xc_dom_binloader.c
@@ -301,7 +301,6 @@ static int xc_dom_load_bin_kernel(struct xc_dom_image *dom)
memcpy(dest, image + skip, text_size);
memset(dest + text_size, 0, bss_size);
- xc_cache_flush(dom->xch, dest, text_size+bss_size);
return 0;
}
diff --git a/tools/libxc/xc_dom_core.c b/tools/libxc/xc_dom_core.c
index d46ac22..77a4e64 100644
--- a/tools/libxc/xc_dom_core.c
+++ b/tools/libxc/xc_dom_core.c
@@ -978,7 +978,6 @@ int xc_dom_build_image(struct xc_dom_image *dom)
}
else
memcpy(ramdiskmap, dom->ramdisk_blob, dom->ramdisk_size);
- xc_cache_flush(dom->xch, ramdiskmap, ramdisklen);
}
/* load devicetree */
@@ -998,7 +997,6 @@ int xc_dom_build_image(struct xc_dom_image *dom)
goto err;
}
memcpy(devicetreemap, dom->devicetree_blob, dom->devicetree_size);
- xc_cache_flush(dom->xch, devicetreemap, dom->devicetree_size);
}
/* allocate other pages */
diff --git a/tools/libxc/xc_linux_osdep.c b/tools/libxc/xc_linux_osdep.c
index e219b24..73860a2 100644
--- a/tools/libxc/xc_linux_osdep.c
+++ b/tools/libxc/xc_linux_osdep.c
@@ -30,7 +30,6 @@
#include <sys/mman.h>
#include <sys/ioctl.h>
-#include <sys/syscall.h>
#include <xen/memory.h>
#include <xen/sys/evtchn.h>
@@ -417,44 +416,6 @@ static void *linux_privcmd_map_foreign_ranges(xc_interface
*xch, xc_osdep_handle
return ret;
}
-static void linux_privcmd_cache_flush(xc_interface *xch,
- const void *ptr, size_t nr)
-{
-#if defined(__arm__)
- unsigned long start = (unsigned long)ptr;
- unsigned long end = start + nr;
- /* cacheflush(unsigned long start, unsigned long end, int flags) */
- int rc = syscall(__ARM_NR_cacheflush, start, end, 0);
- if ( rc < 0 )
- PERROR("cache flush operation failed: %d\n", errno);
-#elif defined(__aarch64__)
- unsigned long start = (unsigned long)ptr;
- unsigned long end = start + nr;
- unsigned long p, ctr;
- int stride;
-
- /* Flush cache using direct DC CVAC instructions. This is
- * available to EL0 when SCTLR_EL1.UCI is set, which Linux does.
- *
- * Bits 19:16 of CTR_EL0 are log2 of the minimum dcache line size
- * in words, which we use as our stride length. This is readable
- * with SCTLR_EL1.UCT is set, which Linux does.
- */
- asm volatile ("mrs %0, ctr_el0" : "=r" (ctr));
-
- stride = 4 * (1 << ((ctr & 0xf0000UL) >> 16));
-
- for ( p = start ; p < end ; p += stride )
- asm volatile ("dc cvac, %0" : : "r" (p));
- asm volatile ("dsb sy");
-#elif defined(__i386__) || defined(__x86_64__)
- /* No need for cache maintenance on x86 */
-#else
- PERROR("No cache flush operation defined for architecture");
- abort();
-#endif
-}
-
static struct xc_osdep_ops linux_privcmd_ops = {
.open = &linux_privcmd_open,
.close = &linux_privcmd_close,
@@ -469,8 +430,6 @@ static struct xc_osdep_ops linux_privcmd_ops = {
.map_foreign_bulk = &linux_privcmd_map_foreign_bulk,
.map_foreign_range = &linux_privcmd_map_foreign_range,
.map_foreign_ranges = &linux_privcmd_map_foreign_ranges,
-
- .cache_flush = &linux_privcmd_cache_flush,
},
};
diff --git a/tools/libxc/xc_minios.c b/tools/libxc/xc_minios.c
index 5026b2b..dec4d73 100644
--- a/tools/libxc/xc_minios.c
+++ b/tools/libxc/xc_minios.c
@@ -181,16 +181,6 @@ static void
*minios_privcmd_map_foreign_ranges(xc_interface *xch, xc_osdep_handl
return ret;
}
-static void minios_privcmd_cache_flush(xc_interface *xch,
- const void *ptr, size_t nr)
-{
-#if defined(__i386__) || defined(__x86_64__)
- /* No need for cache maintenance on x86 */
-#else
- printf("No cache flush operation defined for architecture");
- BUG();
-#endif
-}
static struct xc_osdep_ops minios_privcmd_ops = {
.open = &minios_privcmd_open,
@@ -206,8 +196,6 @@ static struct xc_osdep_ops minios_privcmd_ops = {
.map_foreign_bulk = &minios_privcmd_map_foreign_bulk,
.map_foreign_range = &minios_privcmd_map_foreign_range,
.map_foreign_ranges = &minios_privcmd_map_foreign_ranges,
-
- .cache_flush = &minios_privcmd_cache_flush,
},
};
diff --git a/tools/libxc/xc_netbsd.c b/tools/libxc/xc_netbsd.c
index 0143305..8a90ef3 100644
--- a/tools/libxc/xc_netbsd.c
+++ b/tools/libxc/xc_netbsd.c
@@ -22,7 +22,6 @@
#include <xen/sys/evtchn.h>
#include <unistd.h>
-#include <stdlib.h>
#include <fcntl.h>
#include <malloc.h>
#include <sys/mman.h>
@@ -208,17 +207,6 @@ mmap_failed:
return NULL;
}
-static void netbsd_privcmd_cache_flush(xc_interface *xch,
- const void *ptr, size_t nr)
-{
-#if defined(__i386__) || defined(__x86_64__)
- /* No need for cache maintenance on x86 */
-#else
- PERROR("No cache flush operation defined for architecture");
- abort();
-#endif
-}
-
static struct xc_osdep_ops netbsd_privcmd_ops = {
.open = &netbsd_privcmd_open,
.close = &netbsd_privcmd_close,
@@ -233,8 +221,6 @@ static struct xc_osdep_ops netbsd_privcmd_ops = {
.map_foreign_bulk = &xc_map_foreign_bulk_compat,
.map_foreign_range = &netbsd_privcmd_map_foreign_range,
.map_foreign_ranges = &netbsd_privcmd_map_foreign_ranges,
-
- .cache_flush = &netbsd_privcmd_cache_flush,
},
};
diff --git a/tools/libxc/xc_private.c b/tools/libxc/xc_private.c
index 3ccee2b..838fd21 100644
--- a/tools/libxc/xc_private.c
+++ b/tools/libxc/xc_private.c
@@ -249,11 +249,6 @@ int do_xen_hypercall(xc_interface *xch,
privcmd_hypercall_t *hypercall)
return xch->ops->u.privcmd.hypercall(xch, xch->ops_handle, hypercall);
}
-void xc_cache_flush(xc_interface *xch, const void *p, size_t n)
-{
- xch->ops->u.privcmd.cache_flush(xch, p, n);
-}
-
xc_evtchn *xc_evtchn_open(xentoollog_logger *logger,
unsigned open_flags)
{
diff --git a/tools/libxc/xc_private.h b/tools/libxc/xc_private.h
index 50a0aa7..92271c9 100644
--- a/tools/libxc/xc_private.h
+++ b/tools/libxc/xc_private.h
@@ -304,9 +304,6 @@ void bitmap_byte_to_64(uint64_t *lp, const uint8_t *bp, int
nbits);
/* Optionally flush file to disk and discard page cache */
void discard_file_cache(xc_interface *xch, int fd, int flush);
-/* Flush data cache */
-void xc_cache_flush(xc_interface *xch, const void *p, size_t n);
-
#define MAX_MMU_UPDATES 1024
struct xc_mmu {
mmu_update_t updates[MAX_MMU_UPDATES];
diff --git a/tools/libxc/xc_solaris.c b/tools/libxc/xc_solaris.c
index edffab1..7257a54 100644
--- a/tools/libxc/xc_solaris.c
+++ b/tools/libxc/xc_solaris.c
@@ -23,7 +23,6 @@
#include <xen/memory.h>
#include <xen/sys/evtchn.h>
#include <unistd.h>
-#include <stdlib.h>
#include <fcntl.h>
#include <malloc.h>
@@ -179,17 +178,6 @@ mmap_failed:
return NULL;
}
-static void solaris_privcmd_cache_flush(xc_interface *xch,
- const void *ptr, size_t nr)
-{
-#if defined(__i386__) || defined(__x86_64__)
- /* No need for cache maintenance on x86 */
-#else
- PERROR("No cache flush operation defined for architecture");
- abort();
-#endif
-}
-
static struct xc_osdep_ops solaris_privcmd_ops = {
.open = &solaris_privcmd_open,
.close = &solaris_privcmd_close,
@@ -204,8 +192,6 @@ static struct xc_osdep_ops solaris_privcmd_ops = {
.map_foreign_bulk = &xc_map_foreign_bulk_compat,
.map_foreign_range = &solaris_privcmd_map_foreign_range,
.map_foreign_ranges = &solaris_privcmd_map_foreign_ranges,
-
- .cache_flush = &solaris_privcmd_cache_flush,
},
};
diff --git a/tools/libxc/xenctrl_osdep_ENOSYS.c
b/tools/libxc/xenctrl_osdep_ENOSYS.c
index d911b10..4821342 100644
--- a/tools/libxc/xenctrl_osdep_ENOSYS.c
+++ b/tools/libxc/xenctrl_osdep_ENOSYS.c
@@ -63,13 +63,6 @@ static void *ENOSYS_privcmd_map_foreign_ranges(xc_interface
*xch, xc_osdep_handl
return MAP_FAILED;
}
-static void ENOSYS_privcmd_cache_flush(xc_interface *xch, const void *p,
size_t n)
-{
- unsigned long start = (unsigned long)p;
- unsigned long end = start + n;
- IPRINTF(xch, "ENOSYS_privcmd: cache_flush: %#lx-%#lx\n", start, end);
-}
-
static struct xc_osdep_ops ENOSYS_privcmd_ops =
{
.open = &ENOSYS_privcmd_open,
@@ -81,8 +74,6 @@ static struct xc_osdep_ops ENOSYS_privcmd_ops =
.map_foreign_bulk = &ENOSYS_privcmd_map_foreign_bulk,
.map_foreign_range = &ENOSYS_privcmd_map_foreign_range,
.map_foreign_ranges = &ENOSYS_privcmd_map_foreign_ranges,
-
- .cache_flush = &ENOSYS_privcmd_cache_flush,
}
};
diff --git a/tools/libxc/xenctrlosdep.h b/tools/libxc/xenctrlosdep.h
index 6c9a005..e610a24 100644
--- a/tools/libxc/xenctrlosdep.h
+++ b/tools/libxc/xenctrlosdep.h
@@ -89,7 +89,6 @@ struct xc_osdep_ops
void *(*map_foreign_ranges)(xc_interface *xch, xc_osdep_handle h,
uint32_t dom, size_t size, int prot,
size_t chunksize, privcmd_mmap_entry_t
entries[],
int nentries);
- void (*cache_flush)(xc_interface *xch, const void *p, size_t n);
} privcmd;
struct {
int (*fd)(xc_evtchn *xce, xc_osdep_handle h);
--
1.7.10.4
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