diff mbox series

[17/41] drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status

Message ID 20211104125449.16540-18-tim.gardner@canonical.com
State New
Headers show
Series Enable arm64 | expand

Commit Message

Tim Gardner Nov. 4, 2021, 12:54 p.m. UTC 
From: Joseph Salisbury <joseph.salisbury@microsoft.com>

BugLink: https://bugs.launchpad.net/bugs/1949770

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>
(back ported from commit 753ed9c95c37d058e50e7d42bbe296ee0bf6670d)
[marcelo.cerri@canonical.com: dropped the non existing bits touched by
 the patch]
Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com>
---
 arch/x86/hyperv/hv_apic.c           | 16 +++++++++-------
 arch/x86/hyperv/mmu.c               |  8 ++++----
 arch/x86/hyperv/nested.c            |  8 ++++----
 arch/x86/include/asm/mshyperv.h     |  1 +
 drivers/hv/hv.c                     |  2 +-
 drivers/pci/controller/pci-hyperv.c |  2 +-
 include/asm-generic/mshyperv.h      | 25 ++++++++++++++++++++-----
 7 files changed, 40 insertions(+), 22 deletions(-)
diff mbox series

Patch

diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
index 284e73661a18..ca581b24974a 100644
--- a/arch/x86/hyperv/hv_apic.c
+++ b/arch/x86/hyperv/hv_apic.c
@@ -103,7 +103,7 @@  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;
@@ -128,19 +128,19 @@  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);
 
@@ -184,9 +184,9 @@  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);
@@ -195,6 +195,7 @@  static bool __send_ipi_mask(const struct cpumask *mask, int vector)
 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);
 
@@ -207,7 +208,8 @@  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/mmu.c b/arch/x86/hyperv/mmu.c
index 2c87350c1fb0..c0ba8874d9cb 100644
--- 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 @@  static void hyperv_flush_tlb_others(const struct cpumask *cpus,
 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 dd0a843f766d..5d70968c8538 100644
--- 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 7c3ff0d38e04..10cf34d33ddd 100644
--- 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 917b29e873c5..147abe31b540 100644
--- 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 cd1572bc6c3e..089722630e4a 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -1291,7 +1291,7 @@  static void hv_irq_unmask(struct irq_data *data)
 	 * 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 7821d8180efe..f100baa6a33d 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -39,6 +39,24 @@  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.
@@ -55,12 +73,10 @@  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;
@@ -85,7 +101,6 @@  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)
 {