x86/apic: Allow x2apic without IR on VMware platform
This patch updates x2apic initializaition code to allow x2apic
on VMware platform even without interrupt remapping support.
The hypervisor_x2apic_available hook was added in x2apic
initialization code and used by KVM and XEN, before this.
I have also cleaned up that code to export this hook through the
hypervisor_x86 structure.
Compile tested for KVM and XEN configs, this patch doesn't have
any functional effect on those two platforms.
On VMware platform, verified that x2apic is used in physical
mode on products that support this.
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Reviewed-by: Doug Covelli <dcovelli@vmware.com>
Reviewed-by: Dan Hecht <dhecht@vmware.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Avi Kivity <avi@redhat.com>
Link: http://lkml.kernel.org/r/1358466282.423.60.camel@akataria-dtop.eng.vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index d22d0c4..03a3632 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -33,6 +33,9 @@
#define VMWARE_PORT_CMD_GETVERSION 10
#define VMWARE_PORT_CMD_GETHZ 45
+#define VMWARE_PORT_CMD_GETVCPU_INFO 68
+#define VMWARE_PORT_CMD_LEGACY_X2APIC 3
+#define VMWARE_PORT_CMD_VCPU_RESERVED 31
#define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \
__asm__("inl (%%dx)" : \
@@ -125,10 +128,20 @@
set_cpu_cap(c, X86_FEATURE_TSC_RELIABLE);
}
+/* Checks if hypervisor supports x2apic without VT-D interrupt remapping. */
+static bool __init vmware_legacy_x2apic_available(void)
+{
+ uint32_t eax, ebx, ecx, edx;
+ VMWARE_PORT(GETVCPU_INFO, eax, ebx, ecx, edx);
+ return (eax & (1 << VMWARE_PORT_CMD_VCPU_RESERVED)) == 0 &&
+ (eax & (1 << VMWARE_PORT_CMD_LEGACY_X2APIC)) != 0;
+}
+
const __refconst struct hypervisor_x86 x86_hyper_vmware = {
.name = "VMware",
.detect = vmware_platform,
.set_cpu_features = vmware_set_cpu_features,
.init_platform = vmware_platform_setup,
+ .x2apic_available = vmware_legacy_x2apic_available,
};
EXPORT_SYMBOL(x86_hyper_vmware);