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authorJuergen Gross <jgross@suse.com>2017-04-13 03:37:20 -0400
committerJuergen Gross <jgross@suse.com>2017-05-02 05:14:24 -0400
commitd40342a2ac035444897e5952ea72a50440a2a028 (patch)
tree665a2fcc778d0628cc75f7c74d0d92064ba85703
parent6807cf65f5ba6f2902ab64355d71506b9c14a9dd (diff)
vmware: set cpu capabilities during platform initialization
There is no need to set the same capabilities for each cpu individually. This can be done for all cpus in platform initialization. Cc: Alok Kataria <akataria@vmware.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Cc: virtualization@lists.linux-foundation.org Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Acked-by: Alok Kataria <akataria@vmware.com> Signed-off-by: Juergen Gross <jgross@suse.com>
-rw-r--r--arch/x86/kernel/cpu/vmware.c39
1 files changed, 20 insertions, 19 deletions
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 22403a28caf5..40ed26852ebd 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -113,6 +113,24 @@ static void __init vmware_paravirt_ops_setup(void)
113#define vmware_paravirt_ops_setup() do {} while (0) 113#define vmware_paravirt_ops_setup() do {} while (0)
114#endif 114#endif
115 115
116/*
117 * VMware hypervisor takes care of exporting a reliable TSC to the guest.
118 * Still, due to timing difference when running on virtual cpus, the TSC can
119 * be marked as unstable in some cases. For example, the TSC sync check at
120 * bootup can fail due to a marginal offset between vcpus' TSCs (though the
121 * TSCs do not drift from each other). Also, the ACPI PM timer clocksource
122 * is not suitable as a watchdog when running on a hypervisor because the
123 * kernel may miss a wrap of the counter if the vcpu is descheduled for a
124 * long time. To skip these checks at runtime we set these capability bits,
125 * so that the kernel could just trust the hypervisor with providing a
126 * reliable virtual TSC that is suitable for timekeeping.
127 */
128static void __init vmware_set_capabilities(void)
129{
130 setup_force_cpu_cap(X86_FEATURE_CONSTANT_TSC);
131 setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
132}
133
116static void __init vmware_platform_setup(void) 134static void __init vmware_platform_setup(void)
117{ 135{
118 uint32_t eax, ebx, ecx, edx; 136 uint32_t eax, ebx, ecx, edx;
@@ -152,6 +170,8 @@ static void __init vmware_platform_setup(void)
152#ifdef CONFIG_X86_IO_APIC 170#ifdef CONFIG_X86_IO_APIC
153 no_timer_check = 1; 171 no_timer_check = 1;
154#endif 172#endif
173
174 vmware_set_capabilities();
155} 175}
156 176
157/* 177/*
@@ -176,24 +196,6 @@ static uint32_t __init vmware_platform(void)
176 return 0; 196 return 0;
177} 197}
178 198
179/*
180 * VMware hypervisor takes care of exporting a reliable TSC to the guest.
181 * Still, due to timing difference when running on virtual cpus, the TSC can
182 * be marked as unstable in some cases. For example, the TSC sync check at
183 * bootup can fail due to a marginal offset between vcpus' TSCs (though the
184 * TSCs do not drift from each other). Also, the ACPI PM timer clocksource
185 * is not suitable as a watchdog when running on a hypervisor because the
186 * kernel may miss a wrap of the counter if the vcpu is descheduled for a
187 * long time. To skip these checks at runtime we set these capability bits,
188 * so that the kernel could just trust the hypervisor with providing a
189 * reliable virtual TSC that is suitable for timekeeping.
190 */
191static void vmware_set_cpu_features(struct cpuinfo_x86 *c)
192{
193 set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
194 set_cpu_cap(c, X86_FEATURE_TSC_RELIABLE);
195}
196
197/* Checks if hypervisor supports x2apic without VT-D interrupt remapping. */ 199/* Checks if hypervisor supports x2apic without VT-D interrupt remapping. */
198static bool __init vmware_legacy_x2apic_available(void) 200static bool __init vmware_legacy_x2apic_available(void)
199{ 201{
@@ -206,7 +208,6 @@ static bool __init vmware_legacy_x2apic_available(void)
206const __refconst struct hypervisor_x86 x86_hyper_vmware = { 208const __refconst struct hypervisor_x86 x86_hyper_vmware = {
207 .name = "VMware", 209 .name = "VMware",
208 .detect = vmware_platform, 210 .detect = vmware_platform,
209 .set_cpu_features = vmware_set_cpu_features,
210 .init_platform = vmware_platform_setup, 211 .init_platform = vmware_platform_setup,
211 .x2apic_available = vmware_legacy_x2apic_available, 212 .x2apic_available = vmware_legacy_x2apic_available,
212}; 213};