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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-03 11:02:39 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-03 11:02:39 -0700 |
commit | d7a0dab82fef61bebd34f2bbb9314b075153b646 (patch) | |
tree | 1ec0a1d31ed8231bcce7f20c6b289e57a8969ca9 /arch/x86 | |
parent | 4b978934a440c1aafce986353001b03289eaa040 (diff) | |
parent | 8db549491c4a3ce9e1d509b75f78516e497f48ec (diff) | |
download | linux-d7a0dab82fef61bebd34f2bbb9314b075153b646.tar.bz2 |
Merge branch 'core-smp-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core SMP updates from Ingo Molnar:
"Two main change is generic vCPU pinning and physical CPU SMP-call
support, for Xen to be able to perform certain calls on specific
physical CPUs - by Juergen Gross"
* 'core-smp-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
smp: Allocate smp_call_on_cpu() workqueue on stack too
hwmon: Use smp_call_on_cpu() for dell-smm i8k
dcdbas: Make use of smp_call_on_cpu()
xen: Add xen_pin_vcpu() to support calling functions on a dedicated pCPU
smp: Add function to execute a function synchronously on a CPU
virt, sched: Add generic vCPU pinning support
xen: Sync xen header
Diffstat (limited to 'arch/x86')
-rw-r--r-- | arch/x86/include/asm/hypervisor.h | 4 | ||||
-rw-r--r-- | arch/x86/kernel/cpu/hypervisor.c | 11 | ||||
-rw-r--r-- | arch/x86/xen/enlighten.c | 40 |
3 files changed, 55 insertions, 0 deletions
diff --git a/arch/x86/include/asm/hypervisor.h b/arch/x86/include/asm/hypervisor.h index 055ea9941dd5..67942b6ad4b7 100644 --- a/arch/x86/include/asm/hypervisor.h +++ b/arch/x86/include/asm/hypervisor.h @@ -43,6 +43,9 @@ struct hypervisor_x86 { /* X2APIC detection (run once per boot) */ bool (*x2apic_available)(void); + + /* pin current vcpu to specified physical cpu (run rarely) */ + void (*pin_vcpu)(int); }; extern const struct hypervisor_x86 *x86_hyper; @@ -56,6 +59,7 @@ extern const struct hypervisor_x86 x86_hyper_kvm; extern void init_hypervisor(struct cpuinfo_x86 *c); extern void init_hypervisor_platform(void); extern bool hypervisor_x2apic_available(void); +extern void hypervisor_pin_vcpu(int cpu); #else static inline void init_hypervisor(struct cpuinfo_x86 *c) { } static inline void init_hypervisor_platform(void) { } diff --git a/arch/x86/kernel/cpu/hypervisor.c b/arch/x86/kernel/cpu/hypervisor.c index 27e46658ebe3..35691a6b0d32 100644 --- a/arch/x86/kernel/cpu/hypervisor.c +++ b/arch/x86/kernel/cpu/hypervisor.c @@ -86,3 +86,14 @@ bool __init hypervisor_x2apic_available(void) x86_hyper->x2apic_available && x86_hyper->x2apic_available(); } + +void hypervisor_pin_vcpu(int cpu) +{ + if (!x86_hyper) + return; + + if (x86_hyper->pin_vcpu) + x86_hyper->pin_vcpu(cpu); + else + WARN_ONCE(1, "vcpu pinning requested but not supported!\n"); +} diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index b86ebb1a9a7f..bc9aaba01a22 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1925,6 +1925,45 @@ static void xen_set_cpu_features(struct cpuinfo_x86 *c) } } +static void xen_pin_vcpu(int cpu) +{ + static bool disable_pinning; + struct sched_pin_override pin_override; + int ret; + + if (disable_pinning) + return; + + pin_override.pcpu = cpu; + ret = HYPERVISOR_sched_op(SCHEDOP_pin_override, &pin_override); + + /* Ignore errors when removing override. */ + if (cpu < 0) + return; + + switch (ret) { + case -ENOSYS: + pr_warn("Unable to pin on physical cpu %d. In case of problems consider vcpu pinning.\n", + cpu); + disable_pinning = true; + break; + case -EPERM: + WARN(1, "Trying to pin vcpu without having privilege to do so\n"); + disable_pinning = true; + break; + case -EINVAL: + case -EBUSY: + pr_warn("Physical cpu %d not available for pinning. Check Xen cpu configuration.\n", + cpu); + break; + case 0: + break; + default: + WARN(1, "rc %d while trying to pin vcpu\n", ret); + disable_pinning = true; + } +} + const struct hypervisor_x86 x86_hyper_xen = { .name = "Xen", .detect = xen_platform, @@ -1933,6 +1972,7 @@ const struct hypervisor_x86 x86_hyper_xen = { #endif .x2apic_available = xen_x2apic_para_available, .set_cpu_features = xen_set_cpu_features, + .pin_vcpu = xen_pin_vcpu, }; EXPORT_SYMBOL(x86_hyper_xen); |