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authorK. Y. Srinivasan <kys@microsoft.com>2018-07-03 16:01:55 -0700
committerThomas Gleixner <tglx@linutronix.de>2018-07-06 12:32:59 +0200
commit1268ed0c474a5c8f165ef386f3310521b5e00e27 (patch)
tree6d652266f95cb7b09229ffe476a1572adf95a1f8
parentd0a8d9378d16eb3c69bd8e6d23779fbdbee3a8c7 (diff)
downloadlinux-lora-1268ed0c474a5c8f165ef386f3310521b5e00e27.tar.gz
x86/hyper-v: Fix the circular dependency in IPI enlightenment
The IPI hypercalls depend on being able to map the Linux notion of CPU ID to the hypervisor's notion of the CPU ID. The array hv_vp_index[] provides this mapping. Code for populating this array depends on the IPI functionality. Break this circular dependency. [ tglx: Use a proper define instead of '-1' with a u32 variable as pointed out by Vitaly ] Fixes: 68bb7bfb7985 ("X86/Hyper-V: Enable IPI enlightenments") Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Michael Kelley <mikelley@microsoft.com> Cc: gregkh@linuxfoundation.org Cc: devel@linuxdriverproject.org Cc: olaf@aepfle.de Cc: apw@canonical.com Cc: jasowang@redhat.com Cc: hpa@zytor.com Cc: sthemmin@microsoft.com Cc: Michael.H.Kelley@microsoft.com Cc: vkuznets@redhat.com Link: https://lkml.kernel.org/r/20180703230155.15160-1-kys@linuxonhyperv.com
-rw-r--r--arch/x86/hyperv/hv_apic.c5
-rw-r--r--arch/x86/hyperv/hv_init.c5
-rw-r--r--arch/x86/include/asm/mshyperv.h5
3 files changed, 13 insertions, 2 deletions
diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
index f68855499391f4..40233836565118 100644
--- a/arch/x86/hyperv/hv_apic.c
+++ b/arch/x86/hyperv/hv_apic.c
@@ -114,6 +114,8 @@ static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector)
ipi_arg->vp_set.format = HV_GENERIC_SET_SPARSE_4K;
nr_bank = cpumask_to_vpset(&(ipi_arg->vp_set), mask);
}
+ if (nr_bank < 0)
+ goto ipi_mask_ex_done;
if (!nr_bank)
ipi_arg->vp_set.format = HV_GENERIC_SET_ALL;
@@ -158,6 +160,9 @@ static bool __send_ipi_mask(const struct cpumask *mask, int vector)
for_each_cpu(cur_cpu, mask) {
vcpu = hv_cpu_number_to_vp_number(cur_cpu);
+ if (vcpu == VP_INVAL)
+ goto ipi_mask_done;
+
/*
* This particular version of the IPI hypercall can
* only target upto 64 CPUs.
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 4c431e1c1effc4..1ff420217298ed 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -265,7 +265,7 @@ void __init hyperv_init(void)
{
u64 guest_id, required_msrs;
union hv_x64_msr_hypercall_contents hypercall_msr;
- int cpuhp;
+ int cpuhp, i;
if (x86_hyper_type != X86_HYPER_MS_HYPERV)
return;
@@ -293,6 +293,9 @@ void __init hyperv_init(void)
if (!hv_vp_index)
return;
+ for (i = 0; i < num_possible_cpus(); i++)
+ hv_vp_index[i] = VP_INVAL;
+
hv_vp_assist_page = kcalloc(num_possible_cpus(),
sizeof(*hv_vp_assist_page), GFP_KERNEL);
if (!hv_vp_assist_page) {
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 3cd14311edfad6..5a7375ed5f7cd8 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -9,6 +9,8 @@
#include <asm/hyperv-tlfs.h>
#include <asm/nospec-branch.h>
+#define VP_INVAL U32_MAX
+
struct ms_hyperv_info {
u32 features;
u32 misc_features;
@@ -20,7 +22,6 @@ struct ms_hyperv_info {
extern struct ms_hyperv_info ms_hyperv;
-
/*
* Generate the guest ID.
*/
@@ -281,6 +282,8 @@ static inline int cpumask_to_vpset(struct hv_vpset *vpset,
*/
for_each_cpu(cpu, cpus) {
vcpu = hv_cpu_number_to_vp_number(cpu);
+ if (vcpu == VP_INVAL)
+ return -1;
vcpu_bank = vcpu / 64;
vcpu_offset = vcpu % 64;
__set_bit(vcpu_offset, (unsigned long *)