PCI: hv: Fix hv_arch_irq_unmask() for multi-MSI

commit 455880dfe292a2bdd3b4ad6a107299fce610e64b upstream.

In the multi-MSI case, hv_arch_irq_unmask() will only operate on the first
MSI of the N allocated.  This is because only the first msi_desc is cached
and it is shared by all the MSIs of the multi-MSI block.  This means that
hv_arch_irq_unmask() gets the correct address, but the wrong data (always
0).

This can break MSIs.

Lets assume MSI0 is vector 34 on CPU0, and MSI1 is vector 33 on CPU0.

hv_arch_irq_unmask() is called on MSI0.  It uses a hypercall to configure
the MSI address and data (0) to vector 34 of CPU0.  This is correct.  Then
hv_arch_irq_unmask is called on MSI1.  It uses another hypercall to
configure the MSI address and data (0) to vector 33 of CPU0.  This is
wrong, and results in both MSI0 and MSI1 being routed to vector 33.  Linux
will observe extra instances of MSI1 and no instances of MSI0 despite the
endpoint device behaving correctly.

For the multi-MSI case, we need unique address and data info for each MSI,
but the cached msi_desc does not provide that.  However, that information
can be gotten from the int_desc cached in the chip_data by
compose_msi_msg().  Fix the multi-MSI case to use that cached information
instead.  Since hv_set_msi_entry_from_desc() is no longer applicable,
remove it.

5.15 backport - no changes to code, but merge conflict due to refactor.

Signed-off-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1651068453-29588-1-git-send-email-quic_jhugo@quicinc.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Carl Vanderlip <quic_carlv@quicinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index adccbc209169aa11a2ac8d8f005c61f116bc5cfd..c2b9ab94408e696c4ef03b5b01c352dc8ac5b2ca 100644 (file)
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -176,13 +176,6 @@ bool hv_vcpu_is_preempted(int vcpu);
 static inline void hv_apic_init(void) {}
 #endif
 
-static inline void hv_set_msi_entry_from_desc(union hv_msi_entry *msi_entry,
-                                             struct msi_desc *msi_desc)
-{
-       msi_entry->address.as_uint32 = msi_desc->msg.address_lo;
-       msi_entry->data.as_uint32 = msi_desc->msg.data;
-}
-
 struct irq_domain *hv_create_pci_msi_domain(void);
 
 int hv_map_ioapic_interrupt(int ioapic_id, bool level, int vcpu, int vector,

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 44731a0eb5329ef49f1769f96c065e8efa63cea9..560a9aa297c3a7925acb235e1b78c6deb50a8888 100644 (file)
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -1234,6 +1234,7 @@ static void hv_irq_unmask(struct irq_data *data)
        struct msi_desc *msi_desc = irq_data_get_msi_desc(data);
        struct irq_cfg *cfg = irqd_cfg(data);
        struct hv_retarget_device_interrupt *params;
+       struct tran_int_desc *int_desc;
        struct hv_pcibus_device *hbus;
        struct cpumask *dest;
        cpumask_var_t tmp;
@@ -1248,6 +1249,7 @@ static void hv_irq_unmask(struct irq_data *data)
        pdev = msi_desc_to_pci_dev(msi_desc);
        pbus = pdev->bus;
        hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata);
+       int_desc = data->chip_data;
 
        spin_lock_irqsave(&hbus->retarget_msi_interrupt_lock, flags);
 
@@ -1255,7 +1257,8 @@ static void hv_irq_unmask(struct irq_data *data)
        memset(params, 0, sizeof(*params));
        params->partition_id = HV_PARTITION_ID_SELF;
        params->int_entry.source = HV_INTERRUPT_SOURCE_MSI;
-       hv_set_msi_entry_from_desc(&params->int_entry.msi_entry, msi_desc);
+       params->int_entry.msi_entry.address.as_uint32 = int_desc->address & 0xffffffff;
+       params->int_entry.msi_entry.data.as_uint32 = int_desc->data;
        params->device_id = (hbus->hdev->dev_instance.b[5] << 24) |
                           (hbus->hdev->dev_instance.b[4] << 16) |
                           (hbus->hdev->dev_instance.b[7] << 8) |