* [PATCH 1/2] kvm/qemu: use statfs to determine size of huge pages
2009-03-27 14:34 [PATCH 0/2] Support for GB pages in KVM - userspace part Joerg Roedel
@ 2009-03-27 14:34 ` Joerg Roedel
2009-03-29 11:56 ` Avi Kivity
2009-03-27 14:34 ` [PATCH 2/2] kvm/qemu: set gbpages cpuid bit if kvm supports it Joerg Roedel
1 sibling, 1 reply; 4+ messages in thread
From: Joerg Roedel @ 2009-03-27 14:34 UTC (permalink / raw)
To: Avi Kivity, Marcelo Tosatti; +Cc: kvm, Joerg Roedel
The current method of finding out the size of huge pages does not work
reliable anymore. Current Linux supports more than one huge page size
but /proc/meminfo only show one of the supported sizes.
To find out the real page size used can be found by calling statfs. This
patch changes kvm/qemu to use statfs instead of parsing /proc/meminfo.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
qemu/sysemu.h | 2 +-
qemu/vl.c | 42 +++++++++++++++++++-----------------------
2 files changed, 20 insertions(+), 24 deletions(-)
diff --git a/qemu/sysemu.h b/qemu/sysemu.h
index 4457a40..d765465 100644
--- a/qemu/sysemu.h
+++ b/qemu/sysemu.h
@@ -105,7 +105,7 @@ extern int graphic_rotate;
extern int no_quit;
extern int semihosting_enabled;
extern int old_param;
-extern int hpagesize;
+extern long hpagesize;
extern const char *bootp_filename;
#ifdef USE_KQEMU
diff --git a/qemu/vl.c b/qemu/vl.c
index c52d2d7..f820d3a 100644
--- a/qemu/vl.c
+++ b/qemu/vl.c
@@ -42,6 +42,7 @@
#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__)
@@ -261,7 +262,7 @@ const char *mem_path = NULL;
#ifdef MAP_POPULATE
int mem_prealloc = 1; /* force preallocation of physical target memory */
#endif
-int hpagesize = 0;
+long hpagesize = 0;
const char *cpu_vendor_string;
#ifdef TARGET_ARM
int old_param = 0;
@@ -4747,32 +4748,27 @@ void qemu_get_launch_info(int *argc, char ***argv, int *opt_daemonize, const cha
}
#ifdef USE_KVM
-static int gethugepagesize(void)
+
+#define HUGETLBFS_MAGIC 0x958458f6
+
+static long gethugepagesize(const char *path)
{
- int ret, fd;
- char buf[4096];
- const char *needle = "Hugepagesize:";
- char *size;
- unsigned long hugepagesize;
+ struct statfs fs;
+ int ret;
- fd = open("/proc/meminfo", O_RDONLY);
- if (fd < 0) {
- perror("open");
- exit(0);
- }
+ do {
+ ret = statfs(path, &fs);
+ } while (ret != 0 && errno == EINTR);
- ret = read(fd, buf, sizeof(buf));
- if (ret < 0) {
- perror("read");
- exit(0);
+ if (ret != 0) {
+ perror("statfs");
+ return 0;
}
- size = strstr(buf, needle);
- if (!size)
- return 0;
- size += strlen(needle);
- hugepagesize = strtol(size, NULL, 0);
- return hugepagesize;
+ 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)
@@ -4792,7 +4788,7 @@ static void *alloc_mem_area(size_t memory, unsigned long *len, const char *path)
if (asprintf(&filename, "%s/kvm.XXXXXX", path) == -1)
return NULL;
- hpagesize = gethugepagesize() * 1024;
+ hpagesize = gethugepagesize(path);
if (!hpagesize)
return NULL;
--
1.5.6.4
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 2/2] kvm/qemu: set gbpages cpuid bit if kvm supports it
2009-03-27 14:34 [PATCH 0/2] Support for GB pages in KVM - userspace part Joerg Roedel
2009-03-27 14:34 ` [PATCH 1/2] kvm/qemu: use statfs to determine size of huge pages Joerg Roedel
@ 2009-03-27 14:34 ` Joerg Roedel
1 sibling, 0 replies; 4+ messages in thread
From: Joerg Roedel @ 2009-03-27 14:34 UTC (permalink / raw)
To: Avi Kivity, Marcelo Tosatti; +Cc: kvm, Joerg Roedel
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
libkvm/libkvm.c | 9 +++++++++
libkvm/libkvm.h | 1 +
qemu/qemu-kvm.c | 6 ++++++
qemu/qemu-kvm.h | 3 +++
qemu/target-i386/helper.c | 4 ++++
qemu/vl.c | 7 +++++++
6 files changed, 30 insertions(+), 0 deletions(-)
diff --git a/libkvm/libkvm.c b/libkvm/libkvm.c
index 0610e3f..a699fe9 100644
--- a/libkvm/libkvm.c
+++ b/libkvm/libkvm.c
@@ -1065,6 +1065,15 @@ int kvm_has_sync_mmu(kvm_context_t kvm)
return r;
}
+int kvm_has_gbpages(kvm_context_t kvm)
+{
+ int r = 0;
+#ifdef KVM_CAP_1GB_PAGES
+ r = ioctl(kvm->fd, KVM_CHECK_EXTENSION, KVM_CAP_1GB_PAGES);
+#endif
+ return r;
+}
+
int kvm_inject_nmi(kvm_context_t kvm, int vcpu)
{
#ifdef KVM_CAP_USER_NMI
diff --git a/libkvm/libkvm.h b/libkvm/libkvm.h
index d3e431a..efbc23e 100644
--- a/libkvm/libkvm.h
+++ b/libkvm/libkvm.h
@@ -558,6 +558,7 @@ int kvm_dirty_pages_log_reset(kvm_context_t kvm);
int kvm_irqchip_in_kernel(kvm_context_t kvm);
int kvm_has_sync_mmu(kvm_context_t kvm);
+int kvm_has_gbpages(kvm_context_t kvm);
#ifdef KVM_CAP_IRQCHIP
/*!
diff --git a/qemu/qemu-kvm.c b/qemu/qemu-kvm.c
index 4164368..0a5c6c8 100644
--- a/qemu/qemu-kvm.c
+++ b/qemu/qemu-kvm.c
@@ -33,6 +33,7 @@ int kvm_irqchip = 1;
int kvm_pit = 1;
int kvm_pit_reinject = 1;
int kvm_nested = 0;
+int kvm_gb_pages = 0;
kvm_context_t kvm_context;
pthread_mutex_t qemu_mutex = PTHREAD_MUTEX_INITIALIZER;
@@ -1395,6 +1396,11 @@ int qemu_kvm_has_sync_mmu(void)
return kvm_has_sync_mmu(kvm_context);
}
+int qemu_kvm_has_gbpages()
+{
+ return kvm_has_gbpages(kvm_context);
+}
+
void qemu_kvm_cpu_stop(CPUState *env)
{
if (kvm_enabled())
diff --git a/qemu/qemu-kvm.h b/qemu/qemu-kvm.h
index ca59af8..6f2d99f 100644
--- a/qemu/qemu-kvm.h
+++ b/qemu/qemu-kvm.h
@@ -151,6 +151,7 @@ extern int kvm_irqchip;
extern int kvm_pit;
extern int kvm_pit_reinject;
extern int kvm_nested;
+extern int kvm_gb_pages;
extern kvm_context_t kvm_context;
struct ioperm_data {
@@ -161,6 +162,7 @@ struct ioperm_data {
};
int qemu_kvm_has_sync_mmu(void);
+int qemu_kvm_has_gbpages(void);
void qemu_kvm_cpu_stop(CPUState *env);
#define kvm_enabled() (kvm_allowed)
@@ -172,6 +174,7 @@ void kvm_load_tsc(CPUState *env);
#else
#define kvm_enabled() (0)
#define kvm_nested 0
+#define kvm_gb_pages 0
#define qemu_kvm_irqchip_in_kernel() (0)
#define qemu_kvm_pit_in_kernel() (0)
#define kvm_has_sync_mmu() (0)
diff --git a/qemu/target-i386/helper.c b/qemu/target-i386/helper.c
index be7b021..78a5db5 100644
--- a/qemu/target-i386/helper.c
+++ b/qemu/target-i386/helper.c
@@ -1585,6 +1585,10 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
*ecx &= ~4UL;
/* 3dnow */
*edx &= ~0xc0000000;
+#ifdef USE_KVM
+ if (qemu_kvm_has_gbpages() && kvm_gb_pages)
+ *edx |= CPUID_EXT2_PDPE1GB;
+#endif
}
break;
case 0x80000002:
diff --git a/qemu/vl.c b/qemu/vl.c
index f820d3a..651ef02 100644
--- a/qemu/vl.c
+++ b/qemu/vl.c
@@ -4189,6 +4189,7 @@ static void help(int exitcode)
"-no-kvm-pit disable KVM kernel mode PIT\n"
"-no-kvm-pit-reinjection disable KVM kernel mode PIT interrupt reinjection\n"
"-enable-nesting enable support for running a VM inside the VM (AMD only)\n"
+ "-enable-gb-pages enable GB pages in the guest (if host supports it)\n"
#if defined(TARGET_I386) || defined(TARGET_X86_64) || defined(TARGET_IA64) || defined(__linux__)
"-pcidevice host=bus:dev.func[,dma=none][,name=string]\n"
" expose a PCI device to the guest OS.\n"
@@ -4339,6 +4340,7 @@ enum {
QEMU_OPTION_no_kqemu,
QEMU_OPTION_enable_kvm,
QEMU_OPTION_enable_nesting,
+ QEMU_OPTION_enable_gb_pages,
QEMU_OPTION_no_kvm,
QEMU_OPTION_no_kvm_irqchip,
QEMU_OPTION_no_kvm_pit,
@@ -4488,6 +4490,7 @@ static const QEMUOption qemu_options[] = {
{ "no-kvm-pit", 0, QEMU_OPTION_no_kvm_pit },
{ "no-kvm-pit-reinjection", 0, QEMU_OPTION_no_kvm_pit_reinjection },
{ "enable-nesting", 0, QEMU_OPTION_enable_nesting },
+ { "enable-gb-pages", 0, QEMU_OPTION_enable_gb_pages },
#if defined(TARGET_I386) || defined(TARGET_X86_64) || defined(TARGET_IA64) || defined(__linux__)
{ "pcidevice", HAS_ARG, QEMU_OPTION_pcidevice },
#endif
@@ -5456,6 +5459,10 @@ int main(int argc, char **argv, char **envp)
kvm_nested = 1;
break;
}
+ case QEMU_OPTION_enable_gb_pages: {
+ kvm_gb_pages = 1;
+ break;
+ }
#if defined(TARGET_I386) || defined(TARGET_X86_64) || defined(TARGET_IA64) || defined(__linux__)
case QEMU_OPTION_pcidevice:
if (assigned_devices_index >= MAX_DEV_ASSIGN_CMDLINE) {
--
1.5.6.4
^ permalink raw reply related [flat|nested] 4+ messages in thread