Avi Kivity wrote:
john cooper wrote:
This trivial patch never did manage to find its way
in. Marcelo called it to my attention earlier in
the week. I've tweaked it to apply to kvm-83 and
the resulting patch is attached. I've left the
prior e-mail discussion below for reference.
Sorry for missing this (copying me helps). Please resubmit with a
signoff.Also, please protect with #ifdef MAP_POPULATE to ease merging
into upstream eventually.
Updated patch attached.
-john
Signed-off-by: john cooper <john.cooper@xxxxxxxxxx>
--
john.cooper@xxxxxxxxxx
kernel/x86/Kbuild | 4 ++--
qemu/vl.c | 38 ++++++++++++++++++++++++++++++++++----
2 files changed, 36 insertions(+), 6 deletions(-)
=================================================================
--- a/qemu/vl.c
+++ b/qemu/vl.c
@@ -237,6 +237,9 @@ int semihosting_enabled = 0;
int time_drift_fix = 0;
unsigned int kvm_shadow_memory = 0;
const char *mem_path = NULL;
+#ifdef MAP_POPULATE
+int mem_prealloc = 1; /* force preallocation of physical target memory */
+#endif
int hpagesize = 0;
const char *cpu_vendor_string;
#ifdef TARGET_ARM
@@ -4116,7 +4119,12 @@ static void help(int exitcode)
#endif
"-tdf inject timer interrupts that got lost\n"
"-kvm-shadow-memory megs set the amount of shadow pages to be allocated\n"
- "-mem-path set the path to hugetlbfs/tmpfs mounted directory, also enables allocation of guest memory with huge pages\n"
+ "-mem-path set the path to hugetlbfs/tmpfs mounted directory, also\n"
+ " enables allocation of guest memory with huge pages\n"
+#ifdef MAP_POPULATE
+ "-mem-prealloc toggles preallocation of -mem-path backed physical memory\n"
+ " at startup. Default is enabled.\n"
+#endif
"-option-rom rom load a file, rom, into the option ROM space\n"
#ifdef TARGET_SPARC
"-prom-env variable=value set OpenBIOS nvram variables\n"
@@ -4246,6 +4254,9 @@ enum {
QEMU_OPTION_tdf,
QEMU_OPTION_kvm_shadow_memory,
QEMU_OPTION_mempath,
+#ifdef MAP_POPULATE
+ QEMU_OPTION_mem_prealloc,
+#endif
};
typedef struct QEMUOption {
@@ -4381,6 +4392,9 @@ static const QEMUOption qemu_options[] =
{ "icount", HAS_ARG, QEMU_OPTION_icount },
{ "incoming", HAS_ARG, QEMU_OPTION_incoming },
{ "mem-path", HAS_ARG, QEMU_OPTION_mempath },
+#ifdef MAP_POPULATE
+ { "mem-prealloc", 0, QEMU_OPTION_mem_prealloc },
+#endif
{ NULL },
};
@@ -4663,6 +4677,9 @@ void *alloc_mem_area(size_t memory, unsi
char *filename;
void *area;
int fd;
+#ifdef MAP_POPULATE
+ int flags;
+#endif
if (asprintf(&filename, "%s/kvm.XXXXXX", path) == -1)
return NULL;
@@ -4690,13 +4707,21 @@ void *alloc_mem_area(size_t memory, unsi
*/
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("mmap");
+ perror("alloc_mem_area: can't mmap hugetlbfs pages");
close(fd);
- return NULL;
+ return (NULL);
}
-
*len = memory;
return area;
}
@@ -5377,6 +5402,11 @@ int main(int argc, char **argv, char **e
case QEMU_OPTION_mempath:
mem_path = optarg;
break;
+#ifdef MAP_POPULATE
+ case QEMU_OPTION_mem_prealloc:
+ mem_prealloc = !mem_prealloc;
+ break;
+#endif
case QEMU_OPTION_name:
qemu_name = optarg;
break;
=================================================================
--- a/kernel/x86/Kbuild
+++ b/kernel/x86/Kbuild
@@ -9,8 +9,8 @@ kvm-objs := kvm_main.o x86.o mmu.o x86_e
ifeq ($(EXT_CONFIG_KVM_TRACE),y)
kvm-objs += kvm_trace.o
endif
-ifeq ($(CONFIG_DMAR),y)
-kvm-objs += vtd.o
+ifeq ($(CONFIG_IOMMU_API),y)
+kvm-objs += iommu.o
endif
kvm-intel-objs := vmx.o vmx-debug.o ../external-module-compat.o
kvm-amd-objs := svm.o ../external-module-compat.o
