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| author | Ankur Arora <ankur.a.arora@oracle.com> | 2017-06-03 03:06:01 +0300 |
|---|---|---|
| committer | Juergen Gross <jgross@suse.com> | 2017-06-13 17:10:55 +0300 |
| commit | c9b5d98b25161a7ebee6ea59d6424dd9f33c1b99 (patch) | |
| tree | f2c3526d303d950981f7c09cfe6ee4975896611f /arch/x86/xen/enlighten_hvm.c | |
| parent | 0e4d583723487a975f66f0a8b346fdcb024fafa6 (diff) | |
| download | linux-c9b5d98b25161a7ebee6ea59d6424dd9f33c1b99.tar.xz | |
xen/vcpu: Handle xen_vcpu_setup() failure in hotplug
The hypercall VCPUOP_register_vcpu_info can fail. This failure is
handled by making per_cpu(xen_vcpu, cpu) point to its shared_info
slot and those without one (cpu >= MAX_VIRT_CPUS) be NULL.
For PVH/PVHVM, this is not enough, because we also need to pull
these VCPUs out of circulation.
Fix for PVH/PVHVM: on registration failure in the cpuhp prepare
callback (xen_cpu_up_prepare_hvm()), return an error to the cpuhp
state-machine so it can fail the CPU init.
Fix for PV: the registration happens before smp_init(), so, in the
failure case we clamp setup_max_cpus and limit the number of VCPUs
that smp_init() will bring-up to MAX_VIRT_CPUS.
This is functionally correct but it makes the code a bit simpler
if we get rid of this explicit clamping: for VCPUs that don't have
valid xen_vcpu, fail the CPU init in the cpuhp prepare callback
(xen_cpu_up_prepare_pv()).
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'arch/x86/xen/enlighten_hvm.c')
| -rw-r--r-- | arch/x86/xen/enlighten_hvm.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c index ba1afadb2512..13b5fa1a211c 100644 --- a/arch/x86/xen/enlighten_hvm.c +++ b/arch/x86/xen/enlighten_hvm.c @@ -89,7 +89,7 @@ static void xen_hvm_crash_shutdown(struct pt_regs *regs) static int xen_cpu_up_prepare_hvm(unsigned int cpu) { - int rc; + int rc = 0; /* * This can happen if CPU was offlined earlier and @@ -104,7 +104,9 @@ static int xen_cpu_up_prepare_hvm(unsigned int cpu) per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu); else per_cpu(xen_vcpu_id, cpu) = cpu; - xen_vcpu_setup(cpu); + rc = xen_vcpu_setup(cpu); + if (rc) + return rc; if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock)) xen_setup_timer(cpu); @@ -113,9 +115,8 @@ static int xen_cpu_up_prepare_hvm(unsigned int cpu) if (rc) { WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n", cpu, rc); - return rc; } - return 0; + return rc; } static int xen_cpu_dead_hvm(unsigned int cpu) |