cpu: Improve error reporting on incompatible CPUs

This patch modifies the CPU comparrison function to report the
incompatibilities in more detail to ease identification of problems.

* src/cpu/cpu.h:
    cpuGuestData(): Add argument to return detailed error message.
* src/cpu/cpu.c:
    cpuGuestData(): Add passthrough for error argument.
* src/cpu/cpu_x86.c
    x86FeatureNames(): Add function to convert a CPU definition to flag
                       names.
    x86Compute(): - Add error message parameter
                  - Add macro for reporting detailed error messages.
                  - Improve error reporting.
                  - Simplify calculation of forbidden flags.
    x86DataIteratorInit():
    x86cpuidMatchAny(): Remove functions that are no longer needed.
* src/qemu/qemu_command.c:
    qemuBuildCpuArgStr(): - Modify for new function prototype
                          - Add detailed error reports
                          - Change error code on incompatible processors
                            to VIR_ERR_CONFIG_UNSUPPORTED instead of
                            internal error
* tests/cputest.c:
    cpuTestGuestData(): Modify for new function prototype
This commit is contained in:
Peter Krempa 2012-04-17 15:24:47 +02:00
parent 28ae4f0cbb
commit a2ba53cf18
5 changed files with 101 additions and 50 deletions

View File

@ -248,11 +248,12 @@ cpuNodeData(const char *arch)
virCPUCompareResult
cpuGuestData(virCPUDefPtr host,
virCPUDefPtr guest,
union cpuData **data)
union cpuData **data,
char **msg)
{
struct cpuArchDriver *driver;
VIR_DEBUG("host=%p, guest=%p, data=%p", host, guest, data);
VIR_DEBUG("host=%p, guest=%p, data=%p, msg=%p", host, guest, data, msg);
if ((driver = cpuGetSubDriver(host->arch)) == NULL)
return VIR_CPU_COMPARE_ERROR;
@ -264,7 +265,7 @@ cpuGuestData(virCPUDefPtr host,
return VIR_CPU_COMPARE_ERROR;
}
return driver->guestData(host, guest, data);
return driver->guestData(host, guest, data, msg);
}

View File

@ -70,7 +70,8 @@ typedef union cpuData *
typedef virCPUCompareResult
(*cpuArchGuestData) (virCPUDefPtr host,
virCPUDefPtr guest,
union cpuData **data);
union cpuData **data,
char **message);
typedef virCPUDefPtr
(*cpuArchBaseline) (virCPUDefPtr *cpus,
@ -138,7 +139,8 @@ cpuNodeData (const char *arch);
extern virCPUCompareResult
cpuGuestData(virCPUDefPtr host,
virCPUDefPtr guest,
union cpuData **data);
union cpuData **data,
char **msg);
extern char *
cpuBaselineXML(const char **xmlCPUs,

View File

@ -31,6 +31,7 @@
#include "cpu.h"
#include "cpu_map.h"
#include "cpu_x86.h"
#include "buf.h"
#define VIR_FROM_THIS VIR_FROM_CPU
@ -89,16 +90,6 @@ struct data_iterator {
{ data, -1, false }
static void
x86DataIteratorInit(struct data_iterator *iter,
union cpuData *data)
{
struct data_iterator init = DATA_ITERATOR_INIT(data);
*iter = init;
}
static int
x86cpuidMatch(const struct cpuX86cpuid *cpuid1,
const struct cpuX86cpuid *cpuid2)
@ -121,17 +112,6 @@ x86cpuidMatchMasked(const struct cpuX86cpuid *cpuid,
}
static int
x86cpuidMatchAny(const struct cpuX86cpuid *cpuid,
const struct cpuX86cpuid *mask)
{
return ((cpuid->eax & mask->eax) ||
(cpuid->ebx & mask->ebx) ||
(cpuid->ecx & mask->ecx) ||
(cpuid->edx & mask->edx));
}
static void
x86cpuidSetBits(struct cpuX86cpuid *cpuid,
const struct cpuX86cpuid *mask)
@ -649,6 +629,34 @@ x86FeatureFind(const struct x86_map *map,
}
static char *
x86FeatureNames(const struct x86_map *map,
const char *separator,
union cpuData *data)
{
virBuffer ret = VIR_BUFFER_INITIALIZER;
bool first = true;
struct x86_feature *next_feature = map->features;
virBufferAdd(&ret, "", 0);
while (next_feature) {
if (x86DataIsSubset(data, next_feature->data)) {
if (!first)
virBufferAdd(&ret, separator, -1);
else
first = false;
virBufferAdd(&ret, next_feature->name, -1);
}
next_feature = next_feature->next;
}
return virBufferContentAndReset(&ret);
}
static int
x86FeatureLoad(xmlXPathContextPtr ctxt,
struct x86_map *map)
@ -1115,10 +1123,34 @@ error:
}
/* A helper macro to exit the cpu computation function without writing
* redundant code:
* MSG: error message
* CPU_DEF: a union cpuData pointer with flags that are conflicting
* RET: return code to set
*
* This macro generates the error string outputs it into logs.
*/
#define virX86CpuIncompatible(MSG, CPU_DEF) \
do { \
char *flagsStr = NULL; \
if (!(flagsStr = x86FeatureNames(map, ", ", (CPU_DEF)))) \
goto no_memory; \
if (message && \
virAsprintf(message, "%s: %s", _(MSG), flagsStr) < 0) { \
VIR_FREE(flagsStr); \
goto no_memory; \
} \
VIR_DEBUG("%s: %s", MSG, flagsStr); \
VIR_FREE(flagsStr); \
ret = VIR_CPU_COMPARE_INCOMPATIBLE; \
} while (0)
static virCPUCompareResult
x86Compute(virCPUDefPtr host,
virCPUDefPtr cpu,
union cpuData **guest)
union cpuData **guest,
char **message)
{
struct x86_map *map = NULL;
struct x86_model *host_model = NULL;
@ -1129,8 +1161,6 @@ x86Compute(virCPUDefPtr host,
struct x86_model *cpu_forbid = NULL;
struct x86_model *diff = NULL;
struct x86_model *guest_model = NULL;
struct data_iterator iter;
const struct cpuX86cpuid *cpuid;
virCPUCompareResult ret;
enum compare_result result;
unsigned int i;
@ -1147,6 +1177,11 @@ x86Compute(virCPUDefPtr host,
if (!found) {
VIR_DEBUG("CPU arch %s does not match host arch", cpu->arch);
if (message &&
virAsprintf(message,
_("CPU arch %s does not match host arch"),
cpu->arch) < 0)
goto no_memory;
return VIR_CPU_COMPARE_INCOMPATIBLE;
}
}
@ -1155,6 +1190,12 @@ x86Compute(virCPUDefPtr host,
(!host->vendor || STRNEQ(cpu->vendor, host->vendor))) {
VIR_DEBUG("host CPU vendor does not match required CPU vendor %s",
cpu->vendor);
if (message &&
virAsprintf(message,
_("host CPU vendor does not match required "
"CPU vendor %s"),
cpu->vendor) < 0)
goto no_memory;
return VIR_CPU_COMPARE_INCOMPATIBLE;
}
@ -1167,24 +1208,20 @@ x86Compute(virCPUDefPtr host,
!(cpu_forbid = x86ModelFromCPU(cpu, map, VIR_CPU_FEATURE_FORBID)))
goto error;
x86DataIteratorInit(&iter, cpu_forbid->data);
while ((cpuid = x86DataCpuidNext(&iter))) {
const struct cpuX86cpuid *cpuid2;
cpuid2 = x86DataCpuid(host_model->data, cpuid->function);
if (cpuid2 != NULL && x86cpuidMatchAny(cpuid2, cpuid)) {
VIR_DEBUG("Host CPU provides forbidden features in CPUID function 0x%x",
cpuid->function);
ret = VIR_CPU_COMPARE_INCOMPATIBLE;
goto out;
}
x86DataIntersect(cpu_forbid->data, host_model->data);
if (!x86DataIsEmpty(cpu_forbid->data)) {
virX86CpuIncompatible(N_("Host CPU provides forbidden features"),
cpu_forbid->data);
goto out;
}
x86DataSubtract(cpu_require->data, cpu_disable->data);
result = x86ModelCompare(host_model, cpu_require);
if (result == SUBSET || result == UNRELATED) {
VIR_DEBUG("Host CPU does not provide all required features");
ret = VIR_CPU_COMPARE_INCOMPATIBLE;
x86DataSubtract(cpu_require->data, host_model->data);
virX86CpuIncompatible(N_("Host CPU does not provide required "
"features"),
cpu_require->data);
goto out;
}
@ -1204,8 +1241,9 @@ x86Compute(virCPUDefPtr host,
if (ret == VIR_CPU_COMPARE_SUPERSET
&& cpu->type == VIR_CPU_TYPE_GUEST
&& cpu->match == VIR_CPU_MATCH_STRICT) {
VIR_DEBUG("Host CPU does not strictly match guest CPU");
ret = VIR_CPU_COMPARE_INCOMPATIBLE;
virX86CpuIncompatible(N_("Host CPU does not strictly match guest CPU: "
"Extra features"),
diff->data);
goto out;
}
@ -1246,22 +1284,24 @@ error:
ret = VIR_CPU_COMPARE_ERROR;
goto out;
}
#undef virX86CpuIncompatible
static virCPUCompareResult
x86Compare(virCPUDefPtr host,
virCPUDefPtr cpu)
{
return x86Compute(host, cpu, NULL);
return x86Compute(host, cpu, NULL, NULL);
}
static virCPUCompareResult
x86GuestData(virCPUDefPtr host,
virCPUDefPtr guest,
union cpuData **data)
union cpuData **data,
char **message)
{
return x86Compute(host, guest, data);
return x86Compute(host, guest, data, message);
}

View File

@ -3704,6 +3704,7 @@ qemuBuildCpuArgStr(const struct qemud_driver *driver,
const char *default_model;
union cpuData *data = NULL;
bool have_cpu = false;
char *compare_msg = NULL;
int ret = -1;
virBuffer buf = VIR_BUFFER_INITIALIZER;
int i;
@ -3740,11 +3741,17 @@ qemuBuildCpuArgStr(const struct qemud_driver *driver,
cpuUpdate(cpu, host) < 0)
goto cleanup;
cmp = cpuGuestData(host, cpu, &data);
cmp = cpuGuestData(host, cpu, &data, &compare_msg);
switch (cmp) {
case VIR_CPU_COMPARE_INCOMPATIBLE:
qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s",
if (compare_msg) {
qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("guest and host CPU are not compatible: %s"),
compare_msg);
} else {
qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("guest CPU is not compatible with host CPU"));
}
/* fall through */
case VIR_CPU_COMPARE_ERROR:
goto cleanup;
@ -3848,6 +3855,7 @@ qemuBuildCpuArgStr(const struct qemud_driver *driver,
ret = 0;
cleanup:
VIR_FREE(compare_msg);
if (host)
cpuDataFree(host->arch, data);
virCPUDefFree(guest);

View File

@ -269,7 +269,7 @@ cpuTestGuestData(const void *arg)
!(cpu = cpuTestLoadXML(data->arch, data->name)))
goto cleanup;
cmpResult = cpuGuestData(host, cpu, &guestData);
cmpResult = cpuGuestData(host, cpu, &guestData, NULL);
if (cmpResult == VIR_CPU_COMPARE_ERROR ||
cmpResult == VIR_CPU_COMPARE_INCOMPATIBLE)
goto cleanup;