drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status

There is not a consistent pattern for checking Hyper-V hypercall status.
Existing code uses a number of variants.  The variants work, but a consistent
pattern would improve the readability of the code, and be more conformant
to what the Hyper-V TLFS says about hypercall status.

Implemented new helper functions hv_result(), hv_result_success(), and
hv_repcomp().  Changed the places where hv_do_hypercall() and related variants
are used to use the helper functions.

Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1618620183-9967-2-git-send-email-joseph.salisbury@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
index 082a042..90e682a 100644 (file)
--- a/arch/x86/hyperv/hv_apic.c
+++ b/arch/x86/hyperv/hv_apic.c
@@ -105,7 +105,7 @@ static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector)
        struct hv_send_ipi_ex *ipi_arg;
        unsigned long flags;
        int nr_bank = 0;
-       int ret = 1;
+       u64 status = HV_STATUS_INVALID_PARAMETER;
 
        if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
                return false;
@@ -130,19 +130,19 @@ static bool __send_ipi_mask_ex(const struct cpumask *mask, int vector)
        if (!nr_bank)
                ipi_arg->vp_set.format = HV_GENERIC_SET_ALL;
 
-       ret = hv_do_rep_hypercall(HVCALL_SEND_IPI_EX, 0, nr_bank,
+       status = 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);
+       return hv_result_success(status);
 }
 
 static bool __send_ipi_mask(const struct cpumask *mask, int vector)
 {
        int cur_cpu, vcpu;
        struct hv_send_ipi ipi_arg;
-       int ret = 1;
+       u64 status;
 
        trace_hyperv_send_ipi_mask(mask, vector);
 
@@ -186,9 +186,9 @@ static bool __send_ipi_mask(const struct cpumask *mask, int vector)
                __set_bit(vcpu, (unsigned long *)&ipi_arg.cpu_mask);
        }
 
-       ret = hv_do_fast_hypercall16(HVCALL_SEND_IPI, ipi_arg.vector,
+       status = hv_do_fast_hypercall16(HVCALL_SEND_IPI, ipi_arg.vector,
                                     ipi_arg.cpu_mask);
-       return ((ret == 0) ? true : false);
+       return hv_result_success(status);
 
 do_ex_hypercall:
        return __send_ipi_mask_ex(mask, vector);
@@ -197,6 +197,7 @@ do_ex_hypercall:
 static bool __send_ipi_one(int cpu, int vector)
 {
        int vp = hv_cpu_number_to_vp_number(cpu);
+       u64 status;
 
        trace_hyperv_send_ipi_one(cpu, vector);
 
@@ -209,7 +210,8 @@ static bool __send_ipi_one(int cpu, int vector)
        if (vp >= 64)
                return __send_ipi_mask_ex(cpumask_of(cpu), vector);
 
-       return !hv_do_fast_hypercall16(HVCALL_SEND_IPI, vector, BIT_ULL(vp));
+       status = hv_do_fast_hypercall16(HVCALL_SEND_IPI, vector, BIT_ULL(vp));
+       return hv_result_success(status);
 }
 
 static void hv_send_ipi(int cpu, int vector)

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 7c9da3f..f7dbfa5 100644 (file)
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -347,7 +347,7 @@ static void __init hv_get_partition_id(void)
        local_irq_save(flags);
        output_page = *this_cpu_ptr(hyperv_pcpu_output_arg);
        status = hv_do_hypercall(HVCALL_GET_PARTITION_ID, NULL, output_page);
-       if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS) {
+       if (!hv_result_success(status)) {
                /* No point in proceeding if this failed */
                pr_err("Failed to get partition ID: %lld\n", status);
                BUG();

diff --git a/arch/x86/hyperv/hv_proc.c b/arch/x86/hyperv/hv_proc.c
index 27e17ad..68a0843 100644 (file)
--- a/arch/x86/hyperv/hv_proc.c
+++ b/arch/x86/hyperv/hv_proc.c
@@ -92,10 +92,9 @@ int hv_call_deposit_pages(int node, u64 partition_id, u32 num_pages)
        status = hv_do_rep_hypercall(HVCALL_DEPOSIT_MEMORY,
                                     page_count, 0, input_page, NULL);
        local_irq_restore(flags);
-
-       if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS) {
+       if (!hv_result_success(status)) {
                pr_err("Failed to deposit pages: %lld\n", status);
-               ret = status;
+               ret = hv_result(status);
                goto err_free_allocations;
        }
 
@@ -121,7 +120,7 @@ int hv_call_add_logical_proc(int node, u32 lp_index, u32 apic_id)
        struct hv_add_logical_processor_out *output;
        u64 status;
        unsigned long flags;
-       int ret = 0;
+       int ret = HV_STATUS_SUCCESS;
        int pxm = node_to_pxm(node);
 
        /*
@@ -147,13 +146,11 @@ int hv_call_add_logical_proc(int node, u32 lp_index, u32 apic_id)
                                         input, output);
                local_irq_restore(flags);
 
-               status &= HV_HYPERCALL_RESULT_MASK;
-
-               if (status != HV_STATUS_INSUFFICIENT_MEMORY) {
-                       if (status != HV_STATUS_SUCCESS) {
+               if (hv_result(status) != HV_STATUS_INSUFFICIENT_MEMORY) {
+                       if (!hv_result_success(status)) {
                                pr_err("%s: cpu %u apic ID %u, %lld\n", __func__,
                                       lp_index, apic_id, status);
-                               ret = status;
+                               ret = hv_result(status);
                        }
                        break;
                }
@@ -168,7 +165,7 @@ int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags)
        struct hv_create_vp *input;
        u64 status;
        unsigned long irq_flags;
-       int ret = 0;
+       int ret = HV_STATUS_SUCCESS;
        int pxm = node_to_pxm(node);
 
        /* Root VPs don't seem to need pages deposited */
@@ -199,13 +196,11 @@ int hv_call_create_vp(int node, u64 partition_id, u32 vp_index, u32 flags)
                status = hv_do_hypercall(HVCALL_CREATE_VP, input, NULL);
                local_irq_restore(irq_flags);
 
-               status &= HV_HYPERCALL_RESULT_MASK;
-
-               if (status != HV_STATUS_INSUFFICIENT_MEMORY) {
-                       if (status != HV_STATUS_SUCCESS) {
+               if (hv_result(status) != HV_STATUS_INSUFFICIENT_MEMORY) {
+                       if (!hv_result_success(status)) {
                                pr_err("%s: vcpu %u, lp %u, %lld\n", __func__,
                                       vp_index, flags, status);
-                               ret = status;
+                               ret = hv_result(status);
                        }
                        break;
                }

diff --git a/arch/x86/hyperv/irqdomain.c b/arch/x86/hyperv/irqdomain.c
index 4421a8d..514fc64 100644 (file)
--- a/arch/x86/hyperv/irqdomain.c
+++ b/arch/x86/hyperv/irqdomain.c
@@ -63,10 +63,10 @@ static int hv_map_interrupt(union hv_device_id device_id, bool level,
 
        local_irq_restore(flags);
 
-       if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS)
+       if (!hv_result_success(status))
                pr_err("%s: hypercall failed, status %lld\n", __func__, status);
 
-       return status & HV_HYPERCALL_RESULT_MASK;
+       return hv_result(status);
 }
 
 static int hv_unmap_interrupt(u64 id, struct hv_interrupt_entry *old_entry)
@@ -88,7 +88,7 @@ static int hv_unmap_interrupt(u64 id, struct hv_interrupt_entry *old_entry)
        status = hv_do_hypercall(HVCALL_UNMAP_DEVICE_INTERRUPT, input, NULL);
        local_irq_restore(flags);
 
-       return status & HV_HYPERCALL_RESULT_MASK;
+       return hv_result(status);
 }
 
 #ifdef CONFIG_PCI_MSI

diff --git a/arch/x86/hyperv/mmu.c b/arch/x86/hyperv/mmu.c
index 2c87350..c0ba887 100644 (file)
--- a/arch/x86/hyperv/mmu.c
+++ b/arch/x86/hyperv/mmu.c
@@ -58,7 +58,7 @@ static void hyperv_flush_tlb_others(const struct cpumask *cpus,
        int cpu, vcpu, gva_n, max_gvas;
        struct hv_tlb_flush **flush_pcpu;
        struct hv_tlb_flush *flush;
-       u64 status = U64_MAX;
+       u64 status;
        unsigned long flags;
 
        trace_hyperv_mmu_flush_tlb_others(cpus, info);
@@ -161,7 +161,7 @@ do_ex_hypercall:
 check_status:
        local_irq_restore(flags);
 
-       if (!(status & HV_HYPERCALL_RESULT_MASK))
+       if (hv_result_success(status))
                return;
 do_native:
        native_flush_tlb_others(cpus, info);
@@ -176,7 +176,7 @@ static u64 hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
        u64 status;
 
        if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
-               return U64_MAX;
+               return HV_STATUS_INVALID_PARAMETER;
 
        flush_pcpu = (struct hv_tlb_flush_ex **)
                     this_cpu_ptr(hyperv_pcpu_input_arg);
@@ -201,7 +201,7 @@ static u64 hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
        flush->hv_vp_set.format = HV_GENERIC_SET_SPARSE_4K;
        nr_bank = cpumask_to_vpset(&(flush->hv_vp_set), cpus);
        if (nr_bank < 0)
-               return U64_MAX;
+               return HV_STATUS_INVALID_PARAMETER;
 
        /*
         * We can flush not more than max_gvas with one hypercall. Flush the

diff --git a/arch/x86/hyperv/nested.c b/arch/x86/hyperv/nested.c
index dd0a843..5d70968 100644 (file)
--- a/arch/x86/hyperv/nested.c
+++ b/arch/x86/hyperv/nested.c
@@ -47,7 +47,7 @@ int hyperv_flush_guest_mapping(u64 as)
                                 flush, NULL);
        local_irq_restore(flags);
 
-       if (!(status & HV_HYPERCALL_RESULT_MASK))
+       if (hv_result_success(status))
                ret = 0;
 
 fault:
@@ -92,7 +92,7 @@ int hyperv_flush_guest_mapping_range(u64 as,
 {
        struct hv_guest_mapping_flush_list **flush_pcpu;
        struct hv_guest_mapping_flush_list *flush;
-       u64 status = 0;
+       u64 status;
        unsigned long flags;
        int ret = -ENOTSUPP;
        int gpa_n = 0;
@@ -125,10 +125,10 @@ int hyperv_flush_guest_mapping_range(u64 as,
 
        local_irq_restore(flags);
 
-       if (!(status & HV_HYPERCALL_RESULT_MASK))
+       if (hv_result_success(status))
                ret = 0;
        else
-               ret = status;
+               ret = hv_result(status);
 fault:
        trace_hyperv_nested_flush_guest_mapping_range(as, ret);
        return ret;

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index be5a543..67ff0d6 100644 (file)
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -9,6 +9,7 @@
 #include <asm/hyperv-tlfs.h>
 #include <asm/nospec-branch.h>
 #include <asm/paravirt.h>
+#include <asm/mshyperv.h>
 
 typedef int (*hyperv_fill_flush_list_func)(
                struct hv_guest_mapping_flush_list *flush,

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index e0c522d..e83507f 100644 (file)
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -105,7 +105,7 @@ int hv_post_message(union hv_connection_id connection_id,
         */
        put_cpu_ptr(hv_cpu);
 
-       return status & 0xFFFF;
+       return hv_result(status);
 }
 
 int hv_synic_alloc(void)

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 27a17a1..aa27800 100644 (file)
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -1292,7 +1292,7 @@ exit_unlock:
         * resumes, hv_pci_restore_msi_state() is able to correctly restore
         * the interrupt with the correct affinity.
         */
-       if (res && hbus->state != hv_pcibus_removing)
+       if (!hv_result_success(res) && hbus->state != hv_pcibus_removing)
                dev_err(&hbus->hdev->device,
                        "%s() failed: %#llx", __func__, res);
 

diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index 301db9a..9a000ba 100644 (file)
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -41,6 +41,24 @@ extern struct ms_hyperv_info ms_hyperv;
 extern u64 hv_do_hypercall(u64 control, void *inputaddr, void *outputaddr);
 extern u64 hv_do_fast_hypercall8(u16 control, u64 input8);
 
+/* Helper functions that provide a consistent pattern for checking Hyper-V hypercall status. */
+static inline int hv_result(u64 status)
+{
+       return status & HV_HYPERCALL_RESULT_MASK;
+}
+
+static inline bool hv_result_success(u64 status)
+{
+       return hv_result(status) == HV_STATUS_SUCCESS;
+}
+
+static inline unsigned int hv_repcomp(u64 status)
+{
+       /* Bits [43:32] of status have 'Reps completed' data. */
+       return (status & HV_HYPERCALL_REP_COMP_MASK) >>
+                        HV_HYPERCALL_REP_COMP_OFFSET;
+}
+
 /*
  * Rep hypercalls. Callers of this functions are supposed to ensure that
  * rep_count and varhead_size comply with Hyper-V hypercall definition.
@@ -57,12 +75,10 @@ static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
 
        do {
                status = hv_do_hypercall(control, input, output);
-               if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS)
+               if (!hv_result_success(status))
                        return status;
 
-               /* Bits 32-43 of status have 'Reps completed' data. */
-               rep_comp = (status & HV_HYPERCALL_REP_COMP_MASK) >>
-                       HV_HYPERCALL_REP_COMP_OFFSET;
+               rep_comp = hv_repcomp(status);
 
                control &= ~HV_HYPERCALL_REP_START_MASK;
                control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;
@@ -87,7 +103,6 @@ static inline  __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version,
        return guest_id;
 }
 
-
 /* Free the message slot and signal end-of-message if required */
 static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
 {