[RFC XEN PATCH v5 5/5] domctl: Add XEN_DOMCTL_gsi_permission to grant gsi

[Jiqian Chen <Jiqian.Chen@amd.com>]

Some type of domain don't have PIRQ, like PVH, when
passthrough a device to guest on PVH dom0, callstack
pci_add_dm_done->XEN_DOMCTL_irq_permission will failed
at domain_pirq_to_irq.

So, add a new hypercall to grant/revoke gsi permission
when dom0 is not PV or dom0 has not PIRQ flag.

Co-developed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
---
 tools/include/xenctrl.h      |  5 +++++
 tools/libs/ctrl/xc_domain.c  | 15 +++++++++++++++
 tools/libs/light/libxl_pci.c | 16 ++++++++++++++--
 xen/arch/x86/domctl.c        | 31 +++++++++++++++++++++++++++++++
 xen/include/public/domctl.h  |  9 +++++++++
 xen/xsm/flask/hooks.c        |  1 +
 6 files changed, 75 insertions(+), 2 deletions(-)

diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h
index 2ef8b4e05422..519c860a00d5 100644
--- a/tools/include/xenctrl.h
+++ b/tools/include/xenctrl.h
@@ -1382,6 +1382,11 @@ int xc_domain_irq_permission(xc_interface *xch,
                              uint32_t pirq,
                              bool allow_access);
 
+int xc_domain_gsi_permission(xc_interface *xch,
+                             uint32_t domid,
+                             uint32_t gsi,
+                             bool allow_access);
+
 int xc_domain_iomem_permission(xc_interface *xch,
                                uint32_t domid,
                                unsigned long first_mfn,
diff --git a/tools/libs/ctrl/xc_domain.c b/tools/libs/ctrl/xc_domain.c
index f2d9d14b4d9f..448ba2c59ae1 100644
--- a/tools/libs/ctrl/xc_domain.c
+++ b/tools/libs/ctrl/xc_domain.c
@@ -1394,6 +1394,21 @@ int xc_domain_irq_permission(xc_interface *xch,
     return do_domctl(xch, &domctl);
 }
 
+int xc_domain_gsi_permission(xc_interface *xch,
+                             uint32_t domid,
+                             uint32_t gsi,
+                             bool allow_access)
+{
+    struct xen_domctl domctl = {};
+
+    domctl.cmd = XEN_DOMCTL_gsi_permission;
+    domctl.domain = domid;
+    domctl.u.gsi_permission.gsi = gsi;
+    domctl.u.gsi_permission.allow_access = allow_access;
+
+    return do_domctl(xch, &domctl);
+}
+
 int xc_domain_iomem_permission(xc_interface *xch,
                                uint32_t domid,
                                unsigned long first_mfn,
diff --git a/tools/libs/light/libxl_pci.c b/tools/libs/light/libxl_pci.c
index a1c6e82631e9..4136a860a048 100644
--- a/tools/libs/light/libxl_pci.c
+++ b/tools/libs/light/libxl_pci.c
@@ -1421,6 +1421,8 @@ static void pci_add_dm_done(libxl__egc *egc,
     uint32_t flag = XEN_DOMCTL_DEV_RDM_RELAXED;
     uint32_t domainid = domid;
     bool isstubdom = libxl_is_stubdom(ctx, domid, &domainid);
+    int gsi;
+    bool has_gsi = true;
 
     /* Convenience aliases */
     bool starting = pas->starting;
@@ -1482,6 +1484,7 @@ static void pci_add_dm_done(libxl__egc *egc,
                                 pci->bus, pci->dev, pci->func);
 
     if ( access(sysfs_path, F_OK) != 0 ) {
+        has_gsi = false;
         if ( errno == ENOENT )
             sysfs_path = GCSPRINTF(SYSFS_PCI_DEV"/"PCI_BDF"/irq", pci->domain,
                                 pci->bus, pci->dev, pci->func);
@@ -1497,6 +1500,7 @@ static void pci_add_dm_done(libxl__egc *egc,
         goto out_no_irq;
     }
     if ((fscanf(f, "%u", &irq) == 1) && irq) {
+        gsi = irq;
         r = xc_physdev_map_pirq(ctx->xch, domid, irq, &irq);
         if (r < 0) {
             LOGED(ERROR, domainid, "xc_physdev_map_pirq irq=%d (error=%d)",
@@ -1505,7 +1509,10 @@ static void pci_add_dm_done(libxl__egc *egc,
             rc = ERROR_FAIL;
             goto out;
         }
-        r = xc_domain_irq_permission(ctx->xch, domid, irq, 1);
+        if ( has_gsi )
+            r = xc_domain_gsi_permission(ctx->xch, domid, gsi, 1);
+        if ( !has_gsi || r == -EOPNOTSUPP )
+            r = xc_domain_irq_permission(ctx->xch, domid, irq, 1);
         if (r < 0) {
             LOGED(ERROR, domainid,
                   "xc_domain_irq_permission irq=%d (error=%d)", irq, r);
@@ -2185,6 +2192,7 @@ static void pci_remove_detached(libxl__egc *egc,
     FILE *f;
     uint32_t domainid = prs->domid;
     bool isstubdom;
+    bool has_gsi = true;
 
     /* Convenience aliases */
     libxl_device_pci *const pci = &prs->pci;
@@ -2244,6 +2252,7 @@ skip_bar:
                            pci->bus, pci->dev, pci->func);
 
     if ( access(sysfs_path, F_OK) != 0 ) {
+        has_gsi = false;
         if ( errno == ENOENT )
             sysfs_path = GCSPRINTF(SYSFS_PCI_DEV"/"PCI_BDF"/irq", pci->domain,
                                 pci->bus, pci->dev, pci->func);
@@ -2270,7 +2279,10 @@ skip_bar:
              */
             LOGED(ERROR, domid, "xc_physdev_unmap_pirq irq=%d", irq);
         }
-        rc = xc_domain_irq_permission(ctx->xch, domid, irq, 0);
+        if ( has_gsi )
+            rc = xc_domain_gsi_permission(ctx->xch, domid, irq, 0);
+        if ( !has_gsi || rc == -EOPNOTSUPP )
+            rc = xc_domain_irq_permission(ctx->xch, domid, irq, 0);
         if (rc < 0) {
             LOGED(ERROR, domid, "xc_domain_irq_permission irq=%d", irq);
         }
diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
index 3c0ea8554107..75f23f511ac1 100644
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -237,6 +237,37 @@ long arch_do_domctl(
         break;
     }
 
+    case XEN_DOMCTL_gsi_permission:
+    {
+        unsigned int gsi = domctl->u.gsi_permission.gsi;
+        int allow = domctl->u.gsi_permission.allow_access;
+
+        if ( is_pv_domain(current->domain) || has_pirq(current->domain) )
+        {
+            ret = -EOPNOTSUPP;
+            break;
+        }
+
+        if ( gsi >= nr_irqs_gsi )
+        {
+            ret = -EINVAL;
+            break;
+        }
+
+        if ( !irq_access_permitted(current->domain, gsi) ||
+             xsm_irq_permission(XSM_HOOK, d, gsi, allow) )
+        {
+            ret = -EPERM;
+            break;
+        }
+
+        if ( allow )
+            ret = irq_permit_access(d, gsi);
+        else
+            ret = irq_deny_access(d, gsi);
+        break;
+    }
+
     case XEN_DOMCTL_getpageframeinfo3:
     {
         unsigned int num = domctl->u.getpageframeinfo3.num;
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index a33f9ec32b08..47e95f9ee824 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -447,6 +447,13 @@ struct xen_domctl_irq_permission {
 };
 
 
+/* XEN_DOMCTL_gsi_permission */
+struct xen_domctl_gsi_permission {
+    uint32_t gsi;
+    uint8_t allow_access;    /* flag to specify enable/disable of x86 gsi access */
+};
+
+
 /* XEN_DOMCTL_iomem_permission */
 struct xen_domctl_iomem_permission {
     uint64_aligned_t first_mfn;/* first page (physical page number) in range */
@@ -1277,6 +1284,7 @@ struct xen_domctl {
 #define XEN_DOMCTL_vmtrace_op                    84
 #define XEN_DOMCTL_get_paging_mempool_size       85
 #define XEN_DOMCTL_set_paging_mempool_size       86
+#define XEN_DOMCTL_gsi_permission                87
 #define XEN_DOMCTL_gdbsx_guestmemio            1000
 #define XEN_DOMCTL_gdbsx_pausevcpu             1001
 #define XEN_DOMCTL_gdbsx_unpausevcpu           1002
@@ -1299,6 +1307,7 @@ struct xen_domctl {
         struct xen_domctl_setdomainhandle   setdomainhandle;
         struct xen_domctl_setdebugging      setdebugging;
         struct xen_domctl_irq_permission    irq_permission;
+        struct xen_domctl_gsi_permission    gsi_permission;
         struct xen_domctl_iomem_permission  iomem_permission;
         struct xen_domctl_ioport_permission ioport_permission;
         struct xen_domctl_hypercall_init    hypercall_init;
diff --git a/xen/xsm/flask/hooks.c b/xen/xsm/flask/hooks.c
index 78225f68c15c..376076865198 100644
--- a/xen/xsm/flask/hooks.c
+++ b/xen/xsm/flask/hooks.c
@@ -685,6 +685,7 @@ static int cf_check flask_domctl(struct domain *d, int cmd)
     case XEN_DOMCTL_shadow_op:
     case XEN_DOMCTL_ioport_permission:
     case XEN_DOMCTL_ioport_mapping:
+    case XEN_DOMCTL_gsi_permission:
 #endif
 #ifdef CONFIG_HAS_PASSTHROUGH
     /*
-- 
2.34.1