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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-11 16:19:30 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-11 16:19:30 -0700 |
commit | 607eeb0b836aa24a6972a460a213c4f87902d403 (patch) | |
tree | a3435442118d31e9a9e538333df205c6489c65de /arch/x86/xen | |
parent | 4c4445013f792f82855079ac377bf5d75af4581c (diff) | |
parent | 7c86617dde0015112de566a4619a9b06871580c1 (diff) | |
download | blackbird-op-linux-607eeb0b836aa24a6972a460a213c4f87902d403.tar.gz blackbird-op-linux-607eeb0b836aa24a6972a460a213c4f87902d403.zip |
Merge tag 'stable/for-linus-3.10-rc0-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
Pull Xen bug-fixes from Konrad Rzeszutek Wilk:
- More fixes in the vCPU PVHVM hotplug path.
- Add more documentation.
- Fix various ARM related issues in the Xen generic drivers.
- Updates in the xen-pciback driver per Bjorn's updates.
- Mask the x2APIC feature for PV guests.
* tag 'stable/for-linus-3.10-rc0-tag-two' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen/pci: Used cached MSI-X capability offset
xen/pci: Use PCI_MSIX_TABLE_BIR, not PCI_MSIX_FLAGS_BIRMASK
xen: clear IRQ_NOAUTOEN and IRQ_NOREQUEST
xen: mask x2APIC feature in PV
xen: SWIOTLB is only used on x86
xen/spinlock: Fix check from greater than to be also be greater or equal to.
xen/smp/pvhvm: Don't point per_cpu(xen_vpcu, 33 and larger) to shared_info
xen/vcpu: Document the xen_vcpu_info and xen_vcpu
xen/vcpu/pvhvm: Fix vcpu hotplugging hanging.
Diffstat (limited to 'arch/x86/xen')
-rw-r--r-- | arch/x86/xen/enlighten.c | 50 | ||||
-rw-r--r-- | arch/x86/xen/spinlock.c | 2 |
2 files changed, 50 insertions, 2 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 53d4f680c9b5..a492be2635ac 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -85,7 +85,29 @@ EXPORT_SYMBOL_GPL(hypercall_page); +/* + * Pointer to the xen_vcpu_info structure or + * &HYPERVISOR_shared_info->vcpu_info[cpu]. See xen_hvm_init_shared_info + * and xen_vcpu_setup for details. By default it points to share_info->vcpu_info + * but if the hypervisor supports VCPUOP_register_vcpu_info then it can point + * to xen_vcpu_info. The pointer is used in __xen_evtchn_do_upcall to + * acknowledge pending events. + * Also more subtly it is used by the patched version of irq enable/disable + * e.g. xen_irq_enable_direct and xen_iret in PV mode. + * + * The desire to be able to do those mask/unmask operations as a single + * instruction by using the per-cpu offset held in %gs is the real reason + * vcpu info is in a per-cpu pointer and the original reason for this + * hypercall. + * + */ DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu); + +/* + * Per CPU pages used if hypervisor supports VCPUOP_register_vcpu_info + * hypercall. This can be used both in PV and PVHVM mode. The structure + * overrides the default per_cpu(xen_vcpu, cpu) value. + */ DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info); enum xen_domain_type xen_domain_type = XEN_NATIVE; @@ -157,6 +179,21 @@ static void xen_vcpu_setup(int cpu) BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info); + /* + * This path is called twice on PVHVM - first during bootup via + * smp_init -> xen_hvm_cpu_notify, and then if the VCPU is being + * hotplugged: cpu_up -> xen_hvm_cpu_notify. + * As we can only do the VCPUOP_register_vcpu_info once lets + * not over-write its result. + * + * For PV it is called during restore (xen_vcpu_restore) and bootup + * (xen_setup_vcpu_info_placement). The hotplug mechanism does not + * use this function. + */ + if (xen_hvm_domain()) { + if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu)) + return; + } if (cpu < MAX_VIRT_CPUS) per_cpu(xen_vcpu,cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu]; @@ -172,7 +209,12 @@ static void xen_vcpu_setup(int cpu) /* Check to see if the hypervisor will put the vcpu_info structure where we want it, which allows direct access via - a percpu-variable. */ + a percpu-variable. + N.B. This hypercall can _only_ be called once per CPU. Subsequent + calls will error out with -EINVAL. This is due to the fact that + hypervisor has no unregister variant and this hypercall does not + allow to over-write info.mfn and info.offset. + */ err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info); if (err) { @@ -387,6 +429,9 @@ static void __init xen_init_cpuid_mask(void) cpuid_leaf1_edx_mask &= ~((1 << X86_FEATURE_APIC) | /* disable local APIC */ (1 << X86_FEATURE_ACPI)); /* disable ACPI */ + + cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_X2APIC % 32)); + ax = 1; cx = 0; xen_cpuid(&ax, &bx, &cx, &dx); @@ -1603,6 +1648,9 @@ void __ref xen_hvm_init_shared_info(void) * online but xen_hvm_init_shared_info is run at resume time too and * in that case multiple vcpus might be online. */ for_each_online_cpu(cpu) { + /* Leave it to be NULL. */ + if (cpu >= MAX_VIRT_CPUS) + continue; per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu]; } } diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c index 8b54603ce816..3002ec1bb71a 100644 --- a/arch/x86/xen/spinlock.c +++ b/arch/x86/xen/spinlock.c @@ -364,7 +364,7 @@ void __cpuinit xen_init_lock_cpu(int cpu) int irq; const char *name; - WARN(per_cpu(lock_kicker_irq, cpu) > 0, "spinlock on CPU%d exists on IRQ%d!\n", + WARN(per_cpu(lock_kicker_irq, cpu) >= 0, "spinlock on CPU%d exists on IRQ%d!\n", cpu, per_cpu(lock_kicker_irq, cpu)); /* |