[PATCH 17/41] drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status
Tim Gardner
tim.gardner at canonical.com
Thu Nov 4 12:54:25 UTC 2021
From: Joseph Salisbury <joseph.salisbury at 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 at microsoft.com>
Reviewed-by: Michael Kelley <mikelley at 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 at kernel.org>
(back ported from commit 753ed9c95c37d058e50e7d42bbe296ee0bf6670d)
[marcelo.cerri at canonical.com: dropped the non existing bits touched by
the patch]
Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri at 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 --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)
{
--
2.33.1
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