2018-07-03 22:38:50

by kys

[permalink] [raw]
Subject: [PATCH 1/1] X86: Fix the circular dependency in IPI enlightenment.

From: "K. Y. Srinivasan" <[email protected]>

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.

Fixes: 68bb7bfb7985 ("X86/Hyper-V: Enable IPI enlightenments")

Signed-off-by: K. Y. Srinivasan <[email protected]>
Tested-by: Michael Kelley <[email protected]>
---
arch/x86/hyperv/hv_apic.c | 5 +++++
arch/x86/hyperv/hv_init.c | 3 +++
arch/x86/include/asm/mshyperv.h | 2 ++
3 files changed, 10 insertions(+)

diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
index f68855499391..63d7c196739f 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 == -1)
+ 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 == -1)
+ 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 595e44e8abaa..762ce164d733 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -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] = -1;
+
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 81e768b8d9eb..299de3dcc319 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -285,6 +285,8 @@ 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 == -1)
+ return -1;
vcpu_bank = vcpu / 64;
vcpu_offset = vcpu % 64;
__set_bit(vcpu_offset, (unsigned long *)
--
2.17.1



2018-07-03 22:46:25

by KY Srinivasan

[permalink] [raw]
Subject: RE: [PATCH 1/1] X86: Fix the circular dependency in IPI enlightenment.



> -----Original Message-----
> From: [email protected] <[email protected]>
> Sent: Tuesday, July 3, 2018 3:37 PM
> To: [email protected]; [email protected]; linux-
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; Stephen Hemminger <[email protected]>; Michael
> Kelley (EOSG) <[email protected]>; [email protected]
> Cc: KY Srinivasan <[email protected]>
> Subject: [PATCH 1/1] X86: Fix the circular dependency in IPI enlightenment.
>
> From: "K. Y. Srinivasan" <[email protected]>
>
> 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.
>
> Fixes: 68bb7bfb7985 ("X86/Hyper-V: Enable IPI enlightenments")

Please drop this patch; I have sent the wrong patch.

Regards,

K. Y
>
> Signed-off-by: K. Y. Srinivasan <[email protected]>
> Tested-by: Michael Kelley <[email protected]>
> ---
> arch/x86/hyperv/hv_apic.c | 5 +++++
> arch/x86/hyperv/hv_init.c | 3 +++
> arch/x86/include/asm/mshyperv.h | 2 ++
> 3 files changed, 10 insertions(+)
>
> diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
> index f68855499391..63d7c196739f 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 == -1)
> + 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 == -1)
> + 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 595e44e8abaa..762ce164d733 100644
> --- a/arch/x86/hyperv/hv_init.c
> +++ b/arch/x86/hyperv/hv_init.c
> @@ -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] = -1;
> +
> 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 81e768b8d9eb..299de3dcc319 100644
> --- a/arch/x86/include/asm/mshyperv.h
> +++ b/arch/x86/include/asm/mshyperv.h
> @@ -285,6 +285,8 @@ 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 == -1)
> + return -1;
> vcpu_bank = vcpu / 64;
> vcpu_offset = vcpu % 64;
> __set_bit(vcpu_offset, (unsigned long *)
> --
> 2.17.1