[PATCH 4/4] PCI: hv: Change pci_protocol_version to per-hbus

[Dexuan Cui]

A VM can have multiple hbus. It looks incorrect for the second hbus's
hv_pci_protocol_negotiation() to set the global variable
'pci_protocol_version' (which was set by the first hbus), even if the
same value is written.

Signed-off-by: Dexuan Cui <de...@microsoft.com>
---
 drivers/pci/controller/pci-hyperv.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/drivers/pci/controller/pci-hyperv.c 
b/drivers/pci/controller/pci-hyperv.c
index 2655df2..55730c5 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -76,11 +76,6 @@ enum pci_protocol_version_t {
        PCI_PROTOCOL_VERSION_1_1,
 };
 
-/*
- * Protocol version negotiated by hv_pci_protocol_negotiation().
- */
-static enum pci_protocol_version_t pci_protocol_version;
-
 #define PCI_CONFIG_MMIO_LENGTH 0x2000
 #define CFG_PAGE_OFFSET 0x1000
 #define CFG_PAGE_SIZE (PCI_CONFIG_MMIO_LENGTH - CFG_PAGE_OFFSET)
@@ -429,6 +424,8 @@ enum hv_pcibus_state {
 
 struct hv_pcibus_device {
        struct pci_sysdata sysdata;
+       /* Protocol version negotiated with the host */
+       enum pci_protocol_version_t protocol_version;
        enum hv_pcibus_state state;
        refcount_t remove_lock;
        struct hv_device *hdev;
@@ -942,7 +939,7 @@ static void hv_irq_unmask(struct irq_data *data)
         * negative effect (yet?).
         */
 
-       if (pci_protocol_version >= PCI_PROTOCOL_VERSION_1_2) {
+       if (hbus->protocol_version >= PCI_PROTOCOL_VERSION_1_2) {
                /*
                 * PCI_PROTOCOL_VERSION_1_2 supports the VP_SET version of the
                 * HVCALL_RETARGET_INTERRUPT hypercall, which also coincides
@@ -1112,7 +1109,7 @@ static void hv_compose_msi_msg(struct irq_data *data, 
struct msi_msg *msg)
        ctxt.pci_pkt.completion_func = hv_pci_compose_compl;
        ctxt.pci_pkt.compl_ctxt = &comp;
 
-       switch (pci_protocol_version) {
+       switch (hbus->protocol_version) {
        case PCI_PROTOCOL_VERSION_1_1:
                size = hv_compose_msi_req_v1(&ctxt.int_pkts.v1,
                                        dest,
@@ -2116,6 +2113,7 @@ static int hv_pci_protocol_negotiation(struct hv_device 
*hdev,
                                       enum pci_protocol_version_t version[],
                                       int num_version)
 {
+       struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
        struct pci_version_request *version_req;
        struct hv_pci_compl comp_pkt;
        struct pci_packet *pkt;
@@ -2155,10 +2153,10 @@ static int hv_pci_protocol_negotiation(struct hv_device 
*hdev,
                }
 
                if (comp_pkt.completion_status >= 0) {
-                       pci_protocol_version = version[i];
+                       hbus->protocol_version = version[i];
                        dev_info(&hdev->device,
                                "PCI VMBus probing: Using version %#x\n",
-                               pci_protocol_version);
+                               hbus->protocol_version);
                        goto exit;
                }
 
@@ -2442,7 +2440,7 @@ static int hv_send_resources_allocated(struct hv_device 
*hdev)
        u32 wslot;
        int ret;
 
-       size_res = (pci_protocol_version < PCI_PROTOCOL_VERSION_1_2)
+       size_res = (hbus->protocol_version < PCI_PROTOCOL_VERSION_1_2)
                        ? sizeof(*res_assigned) : sizeof(*res_assigned2);
 
        pkt = kmalloc(sizeof(*pkt) + size_res, GFP_KERNEL);
@@ -2461,7 +2459,7 @@ static int hv_send_resources_allocated(struct hv_device 
*hdev)
                pkt->completion_func = hv_pci_generic_compl;
                pkt->compl_ctxt = &comp_pkt;
 
-               if (pci_protocol_version < PCI_PROTOCOL_VERSION_1_2) {
+               if (hbus->protocol_version < PCI_PROTOCOL_VERSION_1_2) {
                        res_assigned =
                                (struct pci_resources_assigned *)&pkt->message;
                        res_assigned->message_type.type =
@@ -2812,7 +2810,7 @@ static int hv_pci_resume(struct hv_device *hdev)
                return ret;
 
        /* Only use the version that was in use before hibernation. */
-       version[0] = pci_protocol_version;
+       version[0] = hbus->protocol_version;
        ret = hv_pci_protocol_negotiation(hdev, version, 1);
        if (ret)
                goto out;
-- 
1.8.3.1