Mailing List Archive

commit c95358206acd768f06b4fb6c645033094d106775
Author: Ian Jackson <ian.jackson@eu.citrix.com>
Date: Thu Mar 18 16:45:51 2010 +0000

Fix vcpu hotplug bug: get correct vcpu_avail bitmap

Currently qemu has a bug: When maxvcpus > 64, qemu will get wrong
vcpu bitmap (s->cpus_sts[i]) since it only get bitmap from a long variable.

This patch, cooperate with another xend python patch, is to fix this bug.
This patch get hex string from xend, transfer it to correct vcpu_avail bitmap
which saved at an uint32_t array.

Signed-off-By: Liu, Jinsong <jinsong.liu@intel.com>
(This is [PATCH 2/2], the other half is in xen-unstable.hg)
---
hw/piix4acpi.c | 2 +-
i386-dm/helper2.c | 5 +++-
vl.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++---
xen-config-host.h | 2 +-
4 files changed, 56 insertions(+), 7 deletions(-)

diff --git a/hw/piix4acpi.c b/hw/piix4acpi.c
index ccbdf84..fb905d1 100644
--- a/hw/piix4acpi.c
+++ b/hw/piix4acpi.c
@@ -518,7 +518,7 @@ static void gpe_acpi_init(void)
GPEState *s = &gpe_state;
memset(s, 0, sizeof(GPEState));
int i = 0, cpus = vcpus;
- char *vcpumap = (char *)&vcpu_avail;
+ char *vcpumap = (char *)vcpu_avail;

while (cpus > 0) {
s->cpus_sts[i] = vcpumap[i];
diff --git a/i386-dm/helper2.c b/i386-dm/helper2.c
index 090202b..986df3c 100644
--- a/i386-dm/helper2.c
+++ b/i386-dm/helper2.c
@@ -50,6 +50,7 @@

#include <xenctrl.h>
#include <xen/hvm/ioreq.h>
+#include <xen/hvm/hvm_info_table.h>

#include "cpu.h"
#include "exec-all.h"
@@ -78,7 +79,9 @@ _syscall3(int, modify_ldt, int, func, void *, ptr, unsigned long, bytecount)

int domid = -1;
int vcpus = 1;
-uint64_t vcpu_avail = 1;
+/* use 32b array to record whatever vcpu number bitmap */
+/* do not use 64b array to avoid underflow/overflow when strtol */
+uint32_t vcpu_avail[(HVM_MAX_VCPUS + 31)/32] = {0};

int xc_handle = -1;

diff --git a/vl.c b/vl.c
index cb31e5a..30debd7 100644
--- a/vl.c
+++ b/vl.c
@@ -49,6 +49,8 @@

#include "qemu-xen.h"

+#include <xen/hvm/hvm_info_table.h>
+
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
@@ -4704,6 +4706,53 @@ static void termsig_setup(void)

#endif

+#define STEP 8 /* 8 characters fill uint32_t bitmap */
+#define SPACE 8 /* space for non-hex characters in vcpu str */
+#define MAX_VCPU_STR_LEN ((HVM_MAX_VCPUS + 3)/4 + SPACE)
+static int hex_legal(char a)
+{
+ return ((a >= '0' && a <= '9') ||
+ (a >= 'a' && a <= 'f') ||
+ (a >= 'A' && a <= 'F'));
+}
+
+static void vcpu_hex_str_to_bitmap(char *optarg)
+{
+ char str[MAX_VCPU_STR_LEN + 1] = {'\0'};
+ char *pstr;
+ int length;
+ int step = STEP;
+ int i,j = 0;
+
+ length = strlen(optarg);
+ if(length > MAX_VCPU_STR_LEN)
+ exit(EXIT_FAILURE);
+ strncpy(str, optarg, MAX_VCPU_STR_LEN);
+
+ pstr = ((str[1] == 'x') || (str[1] == 'X')) ?
+ str + 2 : str;
+ length = strlen(pstr);
+
+ for(i = 0; i < length; i++)
+ if(hex_legal(pstr[i]))
+ str[j++] = pstr[i];
+ str[j] = '\0';
+ length = strlen(str);
+
+ i = 0;
+ while(length > 0) {
+ char vcpustr[STEP + SPACE] = {'\0'};
+ int start = ((length - step) > 0) ? length - step : 0;
+ int size = ((length - step) > 0) ? step : length;
+ memcpy(vcpustr, str + start, size);
+ errno = 0;
+ vcpu_avail[i++] = strtol(vcpustr, NULL, 16);
+ if(errno)
+ exit(EXIT_FAILURE);
+ length -= step;
+ }
+}
+
int main(int argc, char **argv, char **envp)
{
#ifdef CONFIG_GDBSTUB
@@ -5298,12 +5347,9 @@ int main(int argc, char **argv, char **envp)
break;
case QEMU_OPTION_vcpus:
vcpus = atoi(optarg);
- fprintf(logfile, "qemu: the number of cpus is %d\n", vcpus);
break;
case QEMU_OPTION_vcpu_avail:
- vcpu_avail = atol(optarg);
- fprintf(logfile, "qemu: the avail cpu bitmap is %lx\n",
- vcpu_avail);
+ vcpu_hex_str_to_bitmap(optarg);
break;
case QEMU_OPTION_acpi:
acpi_enabled = 1;
diff --git a/xen-config-host.h b/xen-config-host.h
index e3f546a..6db16d3 100644
--- a/xen-config-host.h
+++ b/xen-config-host.h
@@ -31,7 +31,7 @@ void main_loop_prepare(void);
extern int xc_handle;
extern int xen_pause_requested;
extern int vcpus;
-extern uint64_t vcpu_avail;
+extern uint32_t vcpu_avail[];

#ifdef CONFIG_STUBDOM
#define bdrv_host_device bdrv_raw
--
generated by git-patchbot for /home/xen/git/qemu-xen-unstable.git

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