X86/Hyper-V: Enhanced IPI enlightenment

Support enhanced IPI enlightenments (to target more than 64 CPUs).

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Cc: olaf@aepfle.de
Cc: sthemmin@microsoft.com
Cc: gregkh@linuxfoundation.org
Cc: jasowang@redhat.com
Cc: Michael.H.Kelley@microsoft.com
Cc: hpa@zytor.com
Cc: apw@canonical.com
Cc: devel@linuxdriverproject.org
Cc: vkuznets@redhat.com
Link: https://lkml.kernel.org/r/20180516215334.6547-3-kys@linuxonhyperv.com

4 files changed, 89 insertions, 3 deletions

diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
index 3e0de61f1a7c..192b6ad6a361 100644
--- a/arch/x86/hyperv/hv_apic.c
+++ b/arch/x86/hyperv/hv_apic.c
@@ -93,6 +93,40 @@ static void hv_apic_eoi_write(u32 reg, u32 val)
 /*
  * IPI implementation on Hyper-V.
  */
+static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector)
+{
+        struct ipi_arg_ex **arg;
+        struct ipi_arg_ex *ipi_arg;
+        unsigned long flags;
+        int nr_bank = 0;
+        int ret = 1;
+
+        local_irq_save(flags);
+        arg = (struct ipi_arg_ex **)this_cpu_ptr(hyperv_pcpu_input_arg);
+
+        ipi_arg = *arg;
+        if (unlikely(!ipi_arg))
+                goto ipi_mask_ex_done;
+
+        ipi_arg->vector = vector;
+        ipi_arg->reserved = 0;
+        ipi_arg->vp_set.valid_bank_mask = 0;
+
+        if (!cpumask_equal(mask, cpu_present_mask)) {
+                ipi_arg->vp_set.format = HV_GENERIC_SET_SPARSE_4K;
+                nr_bank = cpumask_to_vpset(&(ipi_arg->vp_set), mask);
+        }
+        if (!nr_bank)
+                ipi_arg->vp_set.format = HV_GENERIC_SET_ALL;
+
+        ret = hv_do_rep_hypercall(HVCALL_SEND_IPI_EX, 0, nr_bank,
+                              ipi_arg, NULL);
+
+ipi_mask_ex_done:
+        local_irq_restore(flags);
+        return ((ret == 0) ? true : false);
+}
+
 static bool __send_ipi_mask(const struct cpumask *mask, int vector)
 {
         int cur_cpu, vcpu;
@@ -110,6 +144,9 @@ static bool __send_ipi_mask(const struct cpumask *mask, int vector)
         if ((vector < HV_IPI_LOW_VECTOR) || (vector > HV_IPI_HIGH_VECTOR))
                 return false;
 
+        if ((ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
+                return __send_ipi_mask_ex(mask, vector);
+
         local_irq_save(flags);
         arg = (struct ipi_arg_non_ex **)this_cpu_ptr(hyperv_pcpu_input_arg);
 
@@ -193,7 +230,10 @@ static void hv_send_ipi_self(int vector)
 void __init hv_apic_init(void)
 {
         if (ms_hyperv.hints & HV_X64_CLUSTER_IPI_RECOMMENDED) {
-                pr_info("Hyper-V: Using IPI hypercalls\n");
+                if ((ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
+                        pr_info("Hyper-V: Using ext hypercalls for IPI\n");
+                else
+                        pr_info("Hyper-V: Using IPI hypercalls\n");
                 /*
                  * Set the IPI entry points.
                  */
diff --git a/arch/x86/hyperv/mmu.c b/arch/x86/hyperv/mmu.c
index 56c9ebac946f..adee39a7a3f2 100644
--- a/arch/x86/hyperv/mmu.c
+++ b/arch/x86/hyperv/mmu.c
@@ -239,7 +239,7 @@ static void hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
         flush->hv_vp_set.valid_bank_mask = 0;
 
         if (!cpumask_equal(cpus, cpu_present_mask)) {
-                flush->hv_vp_set.format = HV_GENERIC_SET_SPARCE_4K;
+                flush->hv_vp_set.format = HV_GENERIC_SET_SPARSE_4K;
                 nr_bank = cpumask_to_vp_set(flush, cpus);
         }
 
diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
index 332e786d4deb..3bfa92c2793c 100644
--- a/arch/x86/include/asm/hyperv-tlfs.h
+++ b/arch/x86/include/asm/hyperv-tlfs.h
@@ -344,6 +344,7 @@ struct hv_tsc_emulation_status {
 #define HVCALL_SEND_IPI                         0x000b
 #define HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX  0x0013
 #define HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX   0x0014
+#define HVCALL_SEND_IPI_EX                      0x0015
 #define HVCALL_POST_MESSAGE                     0x005c
 #define HVCALL_SIGNAL_EVENT                     0x005d
 
@@ -369,7 +370,7 @@ struct hv_tsc_emulation_status {
 #define HV_FLUSH_USE_EXTENDED_RANGE_FORMAT      BIT(3)
 
 enum HV_GENERIC_SET_FORMAT {
-        HV_GENERIC_SET_SPARCE_4K,
+        HV_GENERIC_SET_SPARSE_4K,
         HV_GENERIC_SET_ALL,
 };
 
@@ -721,4 +722,16 @@ struct ipi_arg_non_ex {
         u64 cpu_mask;
 };
 
+struct hv_vpset {
+        u64 format;
+        u64 valid_bank_mask;
+        u64 bank_contents[];
+};
+
+struct ipi_arg_ex {
+        u32 vector;
+        u32 reserved;
+        struct hv_vpset vp_set;
+};
+
 #endif
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 1eff91599c2b..0ee82519957b 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -259,6 +259,39 @@ static inline int hv_cpu_number_to_vp_number(int cpu_number)
         return hv_vp_index[cpu_number];
 }
 
+static inline int cpumask_to_vpset(struct hv_vpset *vpset,
+                                    const struct cpumask *cpus)
+{
+        int cpu, vcpu, vcpu_bank, vcpu_offset, nr_bank = 1;
+
+        /* valid_bank_mask can represent up to 64 banks */
+        if (hv_max_vp_index / 64 >= 64)
+                return 0;
+
+        /*
+         * Clear all banks up to the maximum possible bank as hv_flush_pcpu_ex
+         * structs are not cleared between calls, we risk flushing unneeded
+         * vCPUs otherwise.
+         */
+        for (vcpu_bank = 0; vcpu_bank <= hv_max_vp_index / 64; vcpu_bank++)
+                vpset->bank_contents[vcpu_bank] = 0;
+
+        /*
+         * Some banks may end up being empty but this is acceptable.
+         */
+        for_each_cpu(cpu, cpus) {
+                vcpu = hv_cpu_number_to_vp_number(cpu);
+                vcpu_bank = vcpu / 64;
+                vcpu_offset = vcpu % 64;
+                __set_bit(vcpu_offset, (unsigned long *)
+                          &vpset->bank_contents[vcpu_bank]);
+                if (vcpu_bank >= nr_bank)
+                        nr_bank = vcpu_bank + 1;
+        }
+        vpset->valid_bank_mask = GENMASK_ULL(nr_bank - 1, 0);
+        return nr_bank;
+}
+
 void __init hyperv_init(void);
 void hyperv_setup_mmu_ops(void);
 void hyper_alloc_mmu(void);