[PATCH 1/2] x86/hyperv: Move hv_do_rep_hypercall to asm-generic

[PATCH 1/2] x86/hyperv: Move hv_do_rep_hypercall to asm-generic

[Joseph Salisbury]

From: Joseph Salisbury <joseph.salisbury@microsoft.com>

This patch makes no functional changes.  It simply moves hv_do_rep_hypercall()
out of arch/x86/include/asm/mshyperv.h and into asm-generic/mshyperv.h

hv_do_rep_hypercall() is architecture independent, so it makes sense that it
should be in the architecture independent mshyperv.h, not in the x86-specific
mshyperv.h.

This is done in preperation for a follow up patch which creates a consistent
pattern for checking Hyper-V hypercall status.

Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
---
 arch/x86/include/asm/mshyperv.h | 32 --------------------------------
 include/asm-generic/mshyperv.h  | 31 +++++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 32 deletions(-)

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index ccf60a809a17..bfc98b490f07 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -189,38 +189,6 @@ static inline u64 hv_do_fast_hypercall16(u16 code, u64 input1, u64 input2)
 	return hv_status;
 }
 
-/*
- * Rep hypercalls. Callers of this functions are supposed to ensure that
- * rep_count and varhead_size comply with Hyper-V hypercall definition.
- */
-static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
-				      void *input, void *output)
-{
-	u64 control = code;
-	u64 status;
-	u16 rep_comp;
-
-	control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
-	control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;
-
-	do {
-		status = hv_do_hypercall(control, input, output);
-		if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS)
-			return status;
-
-		/* Bits 32-43 of status have 'Reps completed' data. */
-		rep_comp = (status & HV_HYPERCALL_REP_COMP_MASK) >>
-			HV_HYPERCALL_REP_COMP_OFFSET;
-
-		control &= ~HV_HYPERCALL_REP_START_MASK;
-		control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;
-
-		touch_nmi_watchdog();
-	} while (rep_comp < rep_count);
-
-	return status;
-}
-
 extern struct hv_vp_assist_page **hv_vp_assist_page;
 
 static inline struct hv_vp_assist_page *hv_get_vp_assist_page(unsigned int cpu)
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index dff58a3db5d5..a5246a6ea02d 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -41,6 +41,37 @@ 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);
 
+/*
+ * Rep hypercalls. Callers of this functions are supposed to ensure that
+ * rep_count and varhead_size comply with Hyper-V hypercall definition.
+ */
+static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
+				      void *input, void *output)
+{
+	u64 control = code;
+	u64 status;
+	u16 rep_comp;
+
+	control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
+	control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;
+
+	do {
+		status = hv_do_hypercall(control, input, output);
+		if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS)
+			return status;
+
+		/* Bits 32-43 of status have 'Reps completed' data. */
+		rep_comp = (status & HV_HYPERCALL_REP_COMP_MASK) >>
+			HV_HYPERCALL_REP_COMP_OFFSET;
+
+		control &= ~HV_HYPERCALL_REP_START_MASK;
+		control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;
+
+		touch_nmi_watchdog();
+	} while (rep_comp < rep_count);
+
+	return status;
+}
 
 /* Generate the guest OS identifier as described in the Hyper-V TLFS */
 static inline  __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version,
-- 
2.17.1

[PATCH 2/2] drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status

[Joseph Salisbury]

From: Joseph Salisbury <joseph.salisbury@microsoft.com>

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>
---
 arch/x86/hyperv/hv_apic.c           | 16 +++++++++-------
 arch/x86/hyperv/hv_init.c           |  2 +-
 arch/x86/hyperv/hv_proc.c           | 25 ++++++++++---------------
 arch/x86/hyperv/irqdomain.c         |  6 +++---
 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 ++++++++++++++++++++-----
 10 files changed, 54 insertions(+), 41 deletions(-)

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/hv_init.c b/arch/x86/hyperv/hv_init.c
index b81047dec1da..a5b73584e2cc 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -369,7 +369,7 @@ 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 60461e598239..f16234aef358 100644
--- a/arch/x86/hyperv/hv_proc.c
+++ b/arch/x86/hyperv/hv_proc.c
@@ -93,10 +93,9 @@ 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;
 	}
 
@@ -122,7 +121,7 @@ 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);
 
 	/*
@@ -148,13 +147,11 @@ 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;
 		}
@@ -169,7 +166,7 @@ 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 */
@@ -200,13 +197,11 @@ 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 4421a8d92e23..514fc64e23d5 100644
--- 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 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 bfc98b490f07..759136f98e19 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 f202ac7f4b3d..307fe26dd81a 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -68,7 +68,7 @@ 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 27a17a1e4a7c..aa278005dea2 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -1292,7 +1292,7 @@ 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 a5246a6ea02d..27d85d675e9a 100644
--- 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)
 {
-- 
2.17.1

RE: [PATCH 2/2] drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status

[Michael Kelley]

From: Joseph Salisbury <joseph.salisbury@linux.microsoft.com> Sent: Friday, April 16, 2021 5:43 PM
> 
> 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>
> ---
>  arch/x86/hyperv/hv_apic.c           | 16 +++++++++-------
>  arch/x86/hyperv/hv_init.c           |  2 +-
>  arch/x86/hyperv/hv_proc.c           | 25 ++++++++++---------------
>  arch/x86/hyperv/irqdomain.c         |  6 +++---
>  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 ++++++++++++++++++++-----
>  10 files changed, 54 insertions(+), 41 deletions(-)

Wei -- I have gone through these changes reasonably carefully, but
your review of the Linux-in-the-root-partition changes would be a good
double-check.  It's too easy to get the sense of the tests backwards. :-(

Reviewed-by: Michael Kelley <mikelley@microsoft.com>

> 
> 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/hv_init.c b/arch/x86/hyperv/hv_init.c
> index b81047dec1da..a5b73584e2cc 100644
> --- a/arch/x86/hyperv/hv_init.c
> +++ b/arch/x86/hyperv/hv_init.c
> @@ -369,7 +369,7 @@ 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 60461e598239..f16234aef358 100644
> --- a/arch/x86/hyperv/hv_proc.c
> +++ b/arch/x86/hyperv/hv_proc.c
> @@ -93,10 +93,9 @@ 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;
>  	}
> 
> @@ -122,7 +121,7 @@ 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);
> 
>  	/*
> @@ -148,13 +147,11 @@ 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;
>  		}
> @@ -169,7 +166,7 @@ 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 */
> @@ -200,13 +197,11 @@ 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 4421a8d92e23..514fc64e23d5 100644
> --- 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 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 bfc98b490f07..759136f98e19 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 f202ac7f4b3d..307fe26dd81a 100644
> --- a/drivers/hv/hv.c
> +++ b/drivers/hv/hv.c
> @@ -68,7 +68,7 @@ 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 27a17a1e4a7c..aa278005dea2 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -1292,7 +1292,7 @@ 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 a5246a6ea02d..27d85d675e9a 100644
> --- 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)
>  {
> --
> 2.17.1

Re: [PATCH 2/2] drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status

[Wei Liu]

On Tue, Apr 20, 2021 at 09:30:08PM +0000, Michael Kelley wrote:
> From: Joseph Salisbury <joseph.salisbury@linux.microsoft.com> Sent: Friday, April 16, 2021 5:43 PM
> > 
> > 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>
> > ---
> >  arch/x86/hyperv/hv_apic.c           | 16 +++++++++-------
> >  arch/x86/hyperv/hv_init.c           |  2 +-
> >  arch/x86/hyperv/hv_proc.c           | 25 ++++++++++---------------
> >  arch/x86/hyperv/irqdomain.c         |  6 +++---
> >  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 ++++++++++++++++++++-----
> >  10 files changed, 54 insertions(+), 41 deletions(-)
> 
> Wei -- I have gone through these changes reasonably carefully, but
> your review of the Linux-in-the-root-partition changes would be a good
> double-check.  It's too easy to get the sense of the tests backwards. :-(

The code looks correct to me.

> 
> Reviewed-by: Michael Kelley <mikelley@microsoft.com>

Thanks. I will apply this series to hyperv-next shortly.

Wei.

Re: [PATCH 1/2] x86/hyperv: Move hv_do_rep_hypercall to asm-generic

[Wei Liu]

On Fri, Apr 16, 2021 at 05:43:02PM -0700, Joseph Salisbury wrote:
> From: Joseph Salisbury <joseph.salisbury@microsoft.com>
> 
> This patch makes no functional changes.  It simply moves hv_do_rep_hypercall()
> out of arch/x86/include/asm/mshyperv.h and into asm-generic/mshyperv.h
> 
> hv_do_rep_hypercall() is architecture independent, so it makes sense that it
> should be in the architecture independent mshyperv.h, not in the x86-specific
> mshyperv.h.
> 
> This is done in preperation for a follow up patch which creates a consistent
> pattern for checking Hyper-V hypercall status.
> 
> Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
> ---
[...]
> +static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
> +				      void *input, void *output)
> +{
> +	u64 control = code;
> +	u64 status;
> +	u16 rep_comp;
> +
> +	control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
> +	control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;
> +
> +	do {
> +		status = hv_do_hypercall(control, input, output);
> +		if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS)
> +			return status;
> +
> +		/* Bits 32-43 of status have 'Reps completed' data. */
> +		rep_comp = (status & HV_HYPERCALL_REP_COMP_MASK) >>
> +			HV_HYPERCALL_REP_COMP_OFFSET;
> +
> +		control &= ~HV_HYPERCALL_REP_START_MASK;
> +		control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;
> +
> +		touch_nmi_watchdog();

This seems to be missing in Arm. Does it compile?

Wei.

> +	} while (rep_comp < rep_count);
> +
> +	return status;
> +}
>  
>  /* Generate the guest OS identifier as described in the Hyper-V TLFS */
>  static inline  __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version,
> -- 
> 2.17.1
> 

RE: [PATCH 1/2] x86/hyperv: Move hv_do_rep_hypercall to asm-generic

[Michael Kelley]

From: Wei Liu <wei.liu@kernel.org> Sent: Sunday, April 18, 2021 6:09 AM
> On Fri, Apr 16, 2021 at 05:43:02PM -0700, Joseph Salisbury wrote:
> > From: Joseph Salisbury <joseph.salisbury@microsoft.com>
> >
> > This patch makes no functional changes.  It simply moves hv_do_rep_hypercall()
> > out of arch/x86/include/asm/mshyperv.h and into asm-generic/mshyperv.h
> >
> > hv_do_rep_hypercall() is architecture independent, so it makes sense that it
> > should be in the architecture independent mshyperv.h, not in the x86-specific
> > mshyperv.h.
> >
> > This is done in preperation for a follow up patch which creates a consistent
> > pattern for checking Hyper-V hypercall status.
> >
> > Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
> > ---
> [...]
> > +static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
> > +				      void *input, void *output)
> > +{
> > +	u64 control = code;
> > +	u64 status;
> > +	u16 rep_comp;
> > +
> > +	control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
> > +	control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;
> > +
> > +	do {
> > +		status = hv_do_hypercall(control, input, output);
> > +		if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS)
> > +			return status;
> > +
> > +		/* Bits 32-43 of status have 'Reps completed' data. */
> > +		rep_comp = (status & HV_HYPERCALL_REP_COMP_MASK) >>
> > +			HV_HYPERCALL_REP_COMP_OFFSET;
> > +
> > +		control &= ~HV_HYPERCALL_REP_START_MASK;
> > +		control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;
> > +
> > +		touch_nmi_watchdog();
> 
> This seems to be missing in Arm. Does it compile?
> 
> Wei.

touch_nmi_watchdog() is defined as "static inline" in include/linux/nmi.h.  So
it should be present in all architectures.  It calls arch_touch_nmi_watchdog,
which is an empty function if CONFIG_HAVE_NMI_WATCHDOG is not defined,
as is the case on ARM64.

Michael

> 
> > +	} while (rep_comp < rep_count);
> > +
> > +	return status;
> > +}
> >
> >  /* Generate the guest OS identifier as described in the Hyper-V TLFS */
> >  static inline  __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version,
> > --
> > 2.17.1
> >

Re: [PATCH 1/2] x86/hyperv: Move hv_do_rep_hypercall to asm-generic

[Wei Liu]

On Sun, Apr 18, 2021 at 02:42:55PM +0000, Michael Kelley wrote:
> From: Wei Liu <wei.liu@kernel.org> Sent: Sunday, April 18, 2021 6:09 AM
> > On Fri, Apr 16, 2021 at 05:43:02PM -0700, Joseph Salisbury wrote:
> > > From: Joseph Salisbury <joseph.salisbury@microsoft.com>
> > >
> > > This patch makes no functional changes.  It simply moves hv_do_rep_hypercall()
> > > out of arch/x86/include/asm/mshyperv.h and into asm-generic/mshyperv.h
> > >
> > > hv_do_rep_hypercall() is architecture independent, so it makes sense that it
> > > should be in the architecture independent mshyperv.h, not in the x86-specific
> > > mshyperv.h.
> > >
> > > This is done in preperation for a follow up patch which creates a consistent
> > > pattern for checking Hyper-V hypercall status.
> > >
> > > Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
> > > ---
> > [...]
> > > +static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
> > > +				      void *input, void *output)
> > > +{
> > > +	u64 control = code;
> > > +	u64 status;
> > > +	u16 rep_comp;
> > > +
> > > +	control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
> > > +	control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;
> > > +
> > > +	do {
> > > +		status = hv_do_hypercall(control, input, output);
> > > +		if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS)
> > > +			return status;
> > > +
> > > +		/* Bits 32-43 of status have 'Reps completed' data. */
> > > +		rep_comp = (status & HV_HYPERCALL_REP_COMP_MASK) >>
> > > +			HV_HYPERCALL_REP_COMP_OFFSET;
> > > +
> > > +		control &= ~HV_HYPERCALL_REP_START_MASK;
> > > +		control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;
> > > +
> > > +		touch_nmi_watchdog();
> > 
> > This seems to be missing in Arm. Does it compile?
> > 
> > Wei.
> 
> touch_nmi_watchdog() is defined as "static inline" in include/linux/nmi.h.  So
> it should be present in all architectures.  It calls arch_touch_nmi_watchdog,
> which is an empty function if CONFIG_HAVE_NMI_WATCHDOG is not defined,
> as is the case on ARM64.

I see. I couldn't find arch_touch_nmi_watchdog on Arm but missed the
stub function. Thanks for the information.

Wei.

RE: [PATCH 1/2] x86/hyperv: Move hv_do_rep_hypercall to asm-generic

[Michael Kelley]

From: Joseph Salisbury <joseph.salisbury@linux.microsoft.com> Sent: Friday, April 16, 2021 5:43 PM
> 
> This patch makes no functional changes.  It simply moves hv_do_rep_hypercall()
> out of arch/x86/include/asm/mshyperv.h and into asm-generic/mshyperv.h
> 
> hv_do_rep_hypercall() is architecture independent, so it makes sense that it
> should be in the architecture independent mshyperv.h, not in the x86-specific
> mshyperv.h.
> 
> This is done in preperation for a follow up patch which creates a consistent
> pattern for checking Hyper-V hypercall status.
> 
> Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
> ---
>  arch/x86/include/asm/mshyperv.h | 32 --------------------------------
>  include/asm-generic/mshyperv.h  | 31 +++++++++++++++++++++++++++++++
>  2 files changed, 31 insertions(+), 32 deletions(-)
> 
> diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
> index ccf60a809a17..bfc98b490f07 100644
> --- a/arch/x86/include/asm/mshyperv.h
> +++ b/arch/x86/include/asm/mshyperv.h
> @@ -189,38 +189,6 @@ static inline u64 hv_do_fast_hypercall16(u16 code, u64 input1, u64
> input2)
>  	return hv_status;
>  }
> 
> -/*
> - * Rep hypercalls. Callers of this functions are supposed to ensure that
> - * rep_count and varhead_size comply with Hyper-V hypercall definition.
> - */
> -static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
> -				      void *input, void *output)
> -{
> -	u64 control = code;
> -	u64 status;
> -	u16 rep_comp;
> -
> -	control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
> -	control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;
> -
> -	do {
> -		status = hv_do_hypercall(control, input, output);
> -		if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS)
> -			return status;
> -
> -		/* Bits 32-43 of status have 'Reps completed' data. */
> -		rep_comp = (status & HV_HYPERCALL_REP_COMP_MASK) >>
> -			HV_HYPERCALL_REP_COMP_OFFSET;
> -
> -		control &= ~HV_HYPERCALL_REP_START_MASK;
> -		control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;
> -
> -		touch_nmi_watchdog();
> -	} while (rep_comp < rep_count);
> -
> -	return status;
> -}
> -
>  extern struct hv_vp_assist_page **hv_vp_assist_page;
> 
>  static inline struct hv_vp_assist_page *hv_get_vp_assist_page(unsigned int cpu)
> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
> index dff58a3db5d5..a5246a6ea02d 100644
> --- a/include/asm-generic/mshyperv.h
> +++ b/include/asm-generic/mshyperv.h
> @@ -41,6 +41,37 @@ 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);
> 
> +/*
> + * Rep hypercalls. Callers of this functions are supposed to ensure that
> + * rep_count and varhead_size comply with Hyper-V hypercall definition.
> + */
> +static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
> +				      void *input, void *output)
> +{
> +	u64 control = code;
> +	u64 status;
> +	u16 rep_comp;
> +
> +	control |= (u64)varhead_size << HV_HYPERCALL_VARHEAD_OFFSET;
> +	control |= (u64)rep_count << HV_HYPERCALL_REP_COMP_OFFSET;
> +
> +	do {
> +		status = hv_do_hypercall(control, input, output);
> +		if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS)
> +			return status;
> +
> +		/* Bits 32-43 of status have 'Reps completed' data. */
> +		rep_comp = (status & HV_HYPERCALL_REP_COMP_MASK) >>
> +			HV_HYPERCALL_REP_COMP_OFFSET;
> +
> +		control &= ~HV_HYPERCALL_REP_START_MASK;
> +		control |= (u64)rep_comp << HV_HYPERCALL_REP_START_OFFSET;
> +
> +		touch_nmi_watchdog();
> +	} while (rep_comp < rep_count);
> +
> +	return status;
> +}
> 
>  /* Generate the guest OS identifier as described in the Hyper-V TLFS */
>  static inline  __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version,
> --
> 2.17.1

Reviewed-by: Michael Kelley <mikelley@microsoft.com>