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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>
This commit is contained in:
Juergen Gross 2017-04-13 09:37:20 +02:00
parent 6807cf65f5
commit d40342a2ac
1 changed files with 20 additions and 19 deletions
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39
arch/x86/kernel/cpu/vmware.c
View File

@ -113,6 +113,24 @@ static void __init vmware_paravirt_ops_setup(void)
#define vmware_paravirt_ops_setup() do {} while (0)
#endif
/*
* VMware hypervisor takes care of exporting a reliable TSC to the guest.
* Still, due to timing difference when running on virtual cpus, the TSC can
* be marked as unstable in some cases. For example, the TSC sync check at
* bootup can fail due to a marginal offset between vcpus' TSCs (though the
* TSCs do not drift from each other). Also, the ACPI PM timer clocksource
* is not suitable as a watchdog when running on a hypervisor because the
* kernel may miss a wrap of the counter if the vcpu is descheduled for a
* long time. To skip these checks at runtime we set these capability bits,
* so that the kernel could just trust the hypervisor with providing a
* reliable virtual TSC that is suitable for timekeeping.
*/
static void __init vmware_set_capabilities(void)
{
setup_force_cpu_cap(X86_FEATURE_CONSTANT_TSC);
setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
}
static void __init vmware_platform_setup(void)
{
uint32_t eax, ebx, ecx, edx;
@ -152,6 +170,8 @@ static void __init vmware_platform_setup(void)
#ifdef CONFIG_X86_IO_APIC
no_timer_check = 1;
#endif
vmware_set_capabilities();
}
/*
@ -176,24 +196,6 @@ static uint32_t __init vmware_platform(void)
return 0;
}
/*
* VMware hypervisor takes care of exporting a reliable TSC to the guest.
* Still, due to timing difference when running on virtual cpus, the TSC can
* be marked as unstable in some cases. For example, the TSC sync check at
* bootup can fail due to a marginal offset between vcpus' TSCs (though the
* TSCs do not drift from each other). Also, the ACPI PM timer clocksource
* is not suitable as a watchdog when running on a hypervisor because the
* kernel may miss a wrap of the counter if the vcpu is descheduled for a
* long time. To skip these checks at runtime we set these capability bits,
* so that the kernel could just trust the hypervisor with providing a
* reliable virtual TSC that is suitable for timekeeping.
*/
static void vmware_set_cpu_features(struct cpuinfo_x86 *c)
{
set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
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)
{
@ -206,7 +208,6 @@ static bool __init vmware_legacy_x2apic_available(void)
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,
};