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| author | David Vrabel <david.vrabel@citrix.com> | 2011-07-16 09:33:07 +0100 |
|---|---|---|
| committer | David Vrabel <david.vrabel@citrix.com> | 2011-07-16 09:33:07 +0100 |
| commit | b877dbb2dfcc4886294cf37092559666201c8c3b (patch) | |
| tree | a68dd8a6ce30bc8631ab22810e1d7c68eb151b73 | |
| parent | 10228eb08a279a26805210ec86a136efeefe32d0 (diff) | |
| download | xen-b877dbb2dfcc4886294cf37092559666201c8c3b.tar.gz xen-b877dbb2dfcc4886294cf37092559666201c8c3b.tar.bz2 xen-b877dbb2dfcc4886294cf37092559666201c8c3b.zip | |
xen/libxc: set CPUID topology leaf as unsupported for PV guests
The result of a CPUID Extended Topology Enumeration leaf for PV guests
is invalid as the level in ECX is ignored. This can cause some guests
to loop endlessly when trying to enumerate the topology.
Since the physical topology isn't useful to PV guests set the topology
leaf as unsupported.
Guests affected include Linux kernels prior 2.6.32 where a workaround
was applied ("xen: mask extended topology info in cpu",
82d6469916c6fcfa345636a49004c9d1753905d1).
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
xen-unstable changeset: 23700:867bb675b57b
xen-unstable date: Sat Jul 16 09:05:45 2011 +0100
| -rw-r--r-- | tools/libxc/xc_cpuid_x86.c | 1 | ||||
| -rw-r--r-- | xen/arch/x86/traps.c | 1 |
2 files changed, 2 insertions, 0 deletions
diff --git a/tools/libxc/xc_cpuid_x86.c b/tools/libxc/xc_cpuid_x86.c index 88b41db7b3..6aadce90e7 100644 --- a/tools/libxc/xc_cpuid_x86.c +++ b/tools/libxc/xc_cpuid_x86.c @@ -465,6 +465,7 @@ static void xc_cpuid_pv_policy( case 5: /* MONITOR/MWAIT */ case 0xa: /* Architectural Performance Monitor Features */ + case 0x0000000b: /* Extended Topology Enumeration */ case 0x8000000a: /* SVM revision and features */ case 0x8000001b: /* Instruction Based Sampling */ case 0x8000001c: /* Light Weight Profiling */ diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c index be4c56deb7..504bb08015 100644 --- a/xen/arch/x86/traps.c +++ b/xen/arch/x86/traps.c @@ -828,6 +828,7 @@ static void pv_cpuid(struct cpu_user_regs *regs) /* fall through */ case 5: /* MONITOR/MWAIT */ case 0xa: /* Architectural Performance Monitor Features */ + case 0x0000000b: /* Extended Topology Enumeration */ case 0x8000000a: /* SVM revision and features */ case 0x8000001b: /* Instruction Based Sampling */ case 0x8000001c: /* Light Weight Profiling */ |