[Cc stable]
On Thu, Oct 27, 2022 at 01:52:56PM -0700, Dexuan Cui wrote:
> The local variable 'vector' must be u32 rather than u8: see the
> struct hv_msi_desc3.
>
> 'vector_count' should be u16 rather than u8: see struct hv_msi_desc,
> hv_msi_desc2 and hv_msi_desc3.
>
Dexuan, I think this patch should only be in 5.15, because...
> Fixes: a2bad844a67b ("PCI: hv: Fix interrupt mapping for multi-MSI")
^^^ this commit is already in 5.15.y (commit id 92dcb50f7f09).
Upstream id e70af8d040d2b7904dca93d942ba23fb722e21b1
Cc: <stable@xxxxxxxxxxxxxxx> # 5.15.x
Regards,
Boqun
> Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
> Cc: Jeffrey Hugo <quic_jhugo@xxxxxxxxxxx>
> Cc: Carl Vanderlip <quic_carlv@xxxxxxxxxxx>
> ---
>
> v1 was posted here (sorry, I forgot to follow this up...):
> https://lwn.net/ml/linux-kernel/20220815185505.7626-1-decui@xxxxxxxxxxxxx/
>
> Changes in v2:
> Added the explicit "(u8)" cast in hv_compose_msi_msg().
> Added and improved the comments.
> Fixed a typo in the subject in v1: s/definiton/definition
>
> drivers/pci/controller/pci-hyperv.c | 22 ++++++++++++++++------
> 1 file changed, 16 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> index e7c6f6629e7c..ba64284eaf9f 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -1614,7 +1614,7 @@ static void hv_pci_compose_compl(void *context, struct pci_response *resp,
>
> static u32 hv_compose_msi_req_v1(
> struct pci_create_interrupt *int_pkt, const struct cpumask *affinity,
> - u32 slot, u8 vector, u8 vector_count)
> + u32 slot, u8 vector, u16 vector_count)
> {
> int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE;
> int_pkt->wslot.slot = slot;
> @@ -1642,7 +1642,7 @@ static int hv_compose_msi_req_get_cpu(const struct cpumask *affinity)
>
> static u32 hv_compose_msi_req_v2(
> struct pci_create_interrupt2 *int_pkt, const struct cpumask *affinity,
> - u32 slot, u8 vector, u8 vector_count)
> + u32 slot, u8 vector, u16 vector_count)
> {
> int cpu;
>
> @@ -1661,7 +1661,7 @@ static u32 hv_compose_msi_req_v2(
>
> static u32 hv_compose_msi_req_v3(
> struct pci_create_interrupt3 *int_pkt, const struct cpumask *affinity,
> - u32 slot, u32 vector, u8 vector_count)
> + u32 slot, u32 vector, u16 vector_count)
> {
> int cpu;
>
> @@ -1701,7 +1701,12 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
> struct compose_comp_ctxt comp;
> struct tran_int_desc *int_desc;
> struct msi_desc *msi_desc;
> - u8 vector, vector_count;
> + /*
> + * vector_count should be u16: see hv_msi_desc, hv_msi_desc2
> + * and hv_msi_desc3. vector must be u32: see hv_msi_desc3.
> + */
> + u16 vector_count;
> + u32 vector;
> struct {
> struct pci_packet pci_pkt;
> union {
> @@ -1767,6 +1772,11 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
> vector_count = 1;
> }
>
> + /*
> + * hv_compose_msi_req_v1 and v2 are for x86 only, meaning 'vector'
> + * can't exceed u8. Cast 'vector' down to u8 for v1/v2 explicitly
> + * for better readability.
> + */
> memset(&ctxt, 0, sizeof(ctxt));
> init_completion(&comp.comp_pkt.host_event);
> ctxt.pci_pkt.completion_func = hv_pci_compose_compl;
> @@ -1777,7 +1787,7 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
> size = hv_compose_msi_req_v1(&ctxt.int_pkts.v1,
> dest,
> hpdev->desc.win_slot.slot,
> - vector,
> + (u8)vector,
> vector_count);
> break;
>
> @@ -1786,7 +1796,7 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
> size = hv_compose_msi_req_v2(&ctxt.int_pkts.v2,
> dest,
> hpdev->desc.win_slot.slot,
> - vector,
> + (u8)vector,
> vector_count);
> break;
>
> --
> 2.25.1
>
