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| author | David Vrabel <david.vrabel@citrix.com> | 2011-07-16 09:34:57 +0100 |
|---|---|---|
| committer | David Vrabel <david.vrabel@citrix.com> | 2011-07-16 09:34:57 +0100 |
| commit | 4485d1dc350575fbea3c68d55d9f12c87ef84ef8 (patch) | |
| tree | 5bb2d61b686b84c285e3e2d6361d5a881ea91837 | |
| parent | 8a9f9fa06d63c37b0b9131550dc218d98486ed1b (diff) | |
| download | xen-4485d1dc350575fbea3c68d55d9f12c87ef84ef8.tar.gz xen-4485d1dc350575fbea3c68d55d9f12c87ef84ef8.tar.bz2 xen-4485d1dc350575fbea3c68d55d9f12c87ef84ef8.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 c4ab764cd8..09c1bf0613 100644 --- a/tools/libxc/xc_cpuid_x86.c +++ b/tools/libxc/xc_cpuid_x86.c @@ -349,6 +349,7 @@ static void xc_cpuid_pv_policy( case 0xd: /* XSAVE */ 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 f57b673a6b..85fc0c214e 100644 --- a/xen/arch/x86/traps.c +++ b/xen/arch/x86/traps.c @@ -829,6 +829,7 @@ static void pv_cpuid(struct cpu_user_regs *regs) case 0xd: /* XSAVE */ 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 */ |