[PATCH linux v2 5/9] x86/xen: use xen_vcpu_id mapping when pointing vcpu_info to the shared_info page

From: Vitaly Kuznetsov
Date: Thu Jun 30 2016 - 11:58:28 EST


shared_info page has space for 32 vcpu info slots for first 32 vCPUs but
these are the first 32 vCPUs from Xen's perspective and we should map them
accordingly with the newly introduced xen_vcpu_id mapping.

Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
Changes since v1:
- Use xen_vcpu_nr() helper [David Vrabel]
---
arch/x86/xen/enlighten.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 7e3bf5a..bfdd51b 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -207,8 +207,9 @@ static void xen_vcpu_setup(int cpu)
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];
+ if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS)
+ per_cpu(xen_vcpu, cpu) =
+ &HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];

if (!have_vcpu_info_placement) {
if (cpu >= MAX_VIRT_CPUS)
@@ -1783,9 +1784,10 @@ void __ref xen_hvm_init_shared_info(void)
* in that case multiple vcpus might be online. */
for_each_online_cpu(cpu) {
/* Leave it to be NULL. */
- if (cpu >= MAX_VIRT_CPUS)
+ if (xen_vcpu_nr(cpu) >= MAX_VIRT_CPUS)
continue;
- per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[cpu];
+ per_cpu(xen_vcpu, cpu) =
+ &HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];
}
}

--
2.5.5