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authorAlok N Kataria <akataria@vmware.com>2013-01-18 00:44:42 +0100
committerIngo Molnar <mingo@kernel.org>2013-01-24 13:11:18 +0100
commit4cca6ea04d31c22a7d0436949c072b27bde41f86 (patch)
treee06036506679d25909bd013d3b51f1485b9f2d2f /arch/x86/kernel
parentx86/apic: Remove noisy zero-mask warning from default_send_IPI_mask_logical() (diff)
downloadlinux-4cca6ea04d31c22a7d0436949c072b27bde41f86.tar.xz
linux-4cca6ea04d31c22a7d0436949c072b27bde41f86.zip
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>
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/cpu/hypervisor.c7
-rw-r--r--arch/x86/kernel/cpu/vmware.c13
-rw-r--r--arch/x86/kernel/kvm.c1
3 files changed, 21 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/hypervisor.c b/arch/x86/kernel/cpu/hypervisor.c
index a8f8fa9769d6..1e7e84a02eba 100644
--- a/arch/x86/kernel/cpu/hypervisor.c
+++ b/arch/x86/kernel/cpu/hypervisor.c
@@ -79,3 +79,10 @@ void __init init_hypervisor_platform(void)
if (x86_hyper->init_platform)
x86_hyper->init_platform();
}
+
+bool __init hypervisor_x2apic_available(void)
+{
+ return x86_hyper &&
+ x86_hyper->x2apic_available &&
+ x86_hyper->x2apic_available();
+}
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index d22d0c4edcfd..03a36321ec54 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 @@ static void __cpuinit vmware_set_cpu_features(struct cpuinfo_x86 *c)
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);
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 9c2bd8bd4b4c..2b44ea5f269d 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -505,6 +505,7 @@ static bool __init kvm_detect(void)
const struct hypervisor_x86 x86_hyper_kvm __refconst = {
.name = "KVM",
.detect = kvm_detect,
+ .x2apic_available = kvm_para_available,
};
EXPORT_SYMBOL_GPL(x86_hyper_kvm);