[PATCH 2/5] drivers: hv: Allow vmbus message synic interrupt injected from Hyper-V

Tianyu Lan
2025-09-18T15:01:07Z

When Secure AVIC is enabled, VMBus driver should
call x2apic Secure AVIC interface to allow Hyper-V
to inject VMBus message interrupt.

Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com>
Signed-off-by: Tianyu Lan <tiala@microsoft.com>
---
arch/x86/hyperv/hv_apic.c | 5 +++++
drivers/hv/hv.c | 2 ++
drivers/hv/hv_common.c | 5 +++++
include/asm-generic/mshyperv.h | 1 +
4 files changed, 13 insertions(+)

diff --git a/arch/x86/hyperv/hv_apic.c b/arch/x86/hyperv/hv_apic.c
index e669053b637d..a8de503def37 100644
--- a/arch/x86/hyperv/hv_apic.c
+++ b/arch/x86/hyperv/hv_apic.c
@@ -53,6 +53,11 @@ static void hv_apic_icr_write(u32 low, u32 id)
wrmsrq(HV_X64_MSR_ICR, reg_val);
}

+void hv_enable_coco_interrupt(unsigned int cpu, unsigned int vector, bool set)
+{
+ apic_update_vector(cpu, vector, set);
+}
+
static u32 hv_apic_read(u32 reg)
{
u32 reg_val, hi;
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index b14c5f9e0ef2..ec5d10839e0f 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -307,6 +307,7 @@ void hv_synic_enable_regs(unsigned int cpu)
}

hv_set_msr(HV_MSR_SIEFP, siefp.as_uint64);
+ hv_enable_coco_interrupt(cpu, vmbus_interrupt, true);

/* Setup the shared SINT. */
if (vmbus_irq != -1)
@@ -350,6 +351,7 @@ void hv_synic_disable_regs(unsigned int cpu)
/* Need to correctly cleanup in the case of SMP!!! */
/* Disable the interrupt */
hv_set_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
+ hv_enable_coco_interrupt(cpu, vmbus_interrupt, false);

simp.as_uint64 = hv_get_msr(HV_MSR_SIMP);
/*
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index 49898d10faff..0f024ab3d360 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -716,6 +716,11 @@ u64 __weak hv_tdx_hypercall(u64 control, u64 param1, u64 param2)
}
EXPORT_SYMBOL_GPL(hv_tdx_hypercall);

+void __weak hv_enable_coco_interrupt(unsigned int cpu, unsigned int vector, bool set)
+{
+}
+EXPORT_SYMBOL_GPL(hv_enable_coco_interrupt);
+
void hv_identify_partition_type(void)
{
/* Assume guest role */
diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
index a729b77983fa..7907c9878369 100644
--- a/include/asm-generic/mshyperv.h
+++ b/include/asm-generic/mshyperv.h
@@ -333,6 +333,7 @@ bool hv_is_isolation_supported(void);
bool hv_isolation_type_snp(void);
u64 hv_ghcb_hypercall(u64 control, void *input, void *output, u32 input_size);
u64 hv_tdx_hypercall(u64 control, u64 param1, u64 param2);
+void hv_enable_coco_interrupt(unsigned int cpu, unsigned int vector, bool set);
void hyperv_cleanup(void);
bool hv_query_ext_cap(u64 cap_query);
void hv_setup_dma_ops(struct device *dev, bool coherent);
--
2.25.1