x86/irq: allow setting IRQ permissions from GSI instead of pIRQ

Some domains are not aware of the pIRQ abstraction layer that maps
interrupt sources into Xen space interrupt numbers.  pIRQs values are
only exposed to domains that have the option to route physical
interrupts over event channels.

This creates issues for PCI-passthrough from a PVH domain, as some of
the passthrough related hypercalls use pIRQ as references to physical
interrupts on the system.  One of such interfaces is
XEN_DOMCTL_irq_permission, used to grant or revoke access to
interrupts, takes a pIRQ as the reference to the interrupt to be
adjusted.

Since PVH doesn't manage interrupts in terms of pIRQs, introduce a new
hypercall that allows setting interrupt permissions based on GSI value
rather than pIRQ.

Note the GSI hypercall parameters is translated to an IRQ value (in
case there are ACPI overrides) before doing the checks.

Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Jiqian Chen <Jiqian.Chen@amd.com>
Reviewed-by: Daniel P. Smith <dpsmith@apertussolutions.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
index 6c1355e378efb48120696a3a177d78eee19bccb6..96d816cf1a7dc51497dd9ccc94b8f188b653247d 100644 (file)
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -36,6 +36,7 @@
 #include <asm/xstate.h>
 #include <asm/psr.h>
 #include <asm/cpu-policy.h>
+#include <asm/io_apic.h>
 
 static int update_domain_cpu_policy(struct domain *d,
                                     xen_domctl_cpu_policy_t *xdpc)
@@ -237,6 +238,37 @@ long arch_do_domctl(
         break;
     }
 
+    case XEN_DOMCTL_gsi_permission:
+    {
+        int irq;
+        unsigned int gsi = domctl->u.gsi_permission.gsi;
+        uint32_t flags = domctl->u.gsi_permission.flags;
+
+        /* Check only valid bits are set */
+        ret = -EINVAL;
+        if ( flags & ~XEN_DOMCTL_GSI_ACTION_MASK )
+            break;
+
+        irq = gsi_2_irq(gsi);
+        if ( irq <= 0 )
+        {
+            ret = irq ?: -EACCES;
+            break;
+        }
+
+        ret = -EPERM;
+        if ( !irq_access_permitted(currd, irq) ||
+             xsm_irq_permission(XSM_HOOK, d, irq, flags) )
+            break;
+
+        if ( flags )
+            ret = irq_permit_access(d, irq);
+        else
+            ret = irq_deny_access(d, irq);
+
+        break;
+    }
+
     case XEN_DOMCTL_getpageframeinfo3:
     {
         unsigned int num = domctl->u.getpageframeinfo3.num;

diff --git a/xen/arch/x86/include/asm/io_apic.h b/xen/arch/x86/include/asm/io_apic.h
index 78268ea8f666a7c6a84784b21b3479a4b25ba68d..62456806c7afc7e6cbeb279055289e6f5bdc9350 100644 (file)
--- a/xen/arch/x86/include/asm/io_apic.h
+++ b/xen/arch/x86/include/asm/io_apic.h
@@ -213,5 +213,7 @@ unsigned highest_gsi(void);
 
 int ioapic_guest_read( unsigned long physbase, unsigned int reg, u32 *pval);
 int ioapic_guest_write(unsigned long physbase, unsigned int reg, u32 val);
+int mp_find_ioapic(unsigned int gsi);
+int gsi_2_irq(unsigned int gsi);
 
 #endif

diff --git a/xen/arch/x86/io_apic.c b/xen/arch/x86/io_apic.c
index 7727005846394d9b13818a4162d6d2ffdc6c1733..e40d2f7dbd75f557f7415b362232a7ac9771443d 100644 (file)
--- a/xen/arch/x86/io_apic.c
+++ b/xen/arch/x86/io_apic.c
@@ -955,6 +955,25 @@ static int pin_2_irq(int idx, int apic, int pin)
     return irq;
 }
 
+int gsi_2_irq(unsigned int gsi)
+{
+    int ioapic, irq;
+    unsigned int pin;
+
+    if ( gsi > highest_gsi() )
+        return -ERANGE;
+
+    ioapic = mp_find_ioapic(gsi);
+    if ( ioapic < 0 )
+        return -EINVAL;
+
+    pin = gsi - io_apic_gsi_base(ioapic);
+
+    irq = apic_pin_2_gsi_irq(ioapic, pin);
+
+    return irq ?: -EINVAL;
+}
+
 static inline int IO_APIC_irq_trigger(int irq)
 {
     int apic, idx, pin;

diff --git a/xen/arch/x86/mpparse.c b/xen/arch/x86/mpparse.c
index 306d8ed97a8385f157aef9ab1436f5b212775e5d..e13b83bbe9dd1cba8f45f3c74efb1298072f8da1 100644 (file)
--- a/xen/arch/x86/mpparse.c
+++ b/xen/arch/x86/mpparse.c
@@ -842,8 +842,7 @@ static struct mp_ioapic_routing {
 } mp_ioapic_routing[MAX_IO_APICS];
 
 
-static int mp_find_ioapic (
-       int                     gsi)
+int mp_find_ioapic(unsigned int gsi)
 {
        unsigned int            i;
 
@@ -854,7 +853,7 @@ static int mp_find_ioapic (
                        return i;
        }
 
-       printk(KERN_ERR "ERROR: Unable to locate IOAPIC for GSI %d\n", gsi);
+       printk(KERN_ERR "ERROR: Unable to locate IOAPIC for GSI %u\n", gsi);
 
        return -1;
 }
@@ -915,7 +914,7 @@ void __init mp_register_ioapic (
        return;
 }
 
-unsigned __init highest_gsi(void)
+unsigned highest_gsi(void)
 {
        unsigned x, res = 0;
        for (x = 0; x < nr_ioapics; x++)

diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index 2a49fe46ce25349d49a31d39fe83e04e9a1e2abf..e1028fc524cf9e763c2651080829eed7312da996 100644 (file)
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -464,6 +464,14 @@ struct xen_domctl_irq_permission {
     uint8_t pad[3];
 };
 
+/* XEN_DOMCTL_gsi_permission */
+struct xen_domctl_gsi_permission {
+    uint32_t gsi;
+#define XEN_DOMCTL_GSI_REVOKE      0
+#define XEN_DOMCTL_GSI_GRANT       1
+#define XEN_DOMCTL_GSI_ACTION_MASK 1
+    uint32_t flags;
+};
 
 /* XEN_DOMCTL_iomem_permission */
 struct xen_domctl_iomem_permission {
@@ -1306,6 +1314,7 @@ struct xen_domctl {
 #define XEN_DOMCTL_get_paging_mempool_size       85
 #define XEN_DOMCTL_set_paging_mempool_size       86
 #define XEN_DOMCTL_dt_overlay                    87
+#define XEN_DOMCTL_gsi_permission                88
 #define XEN_DOMCTL_gdbsx_guestmemio            1000
 #define XEN_DOMCTL_gdbsx_pausevcpu             1001
 #define XEN_DOMCTL_gdbsx_unpausevcpu           1002
@@ -1328,6 +1337,7 @@ 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 278ad38c2af324aa1e35119305abf9eb9c7c724a..dfa23738cd8a9fd91eda23d9c328c3cc55d31418 100644 (file)
--- a/xen/xsm/flask/hooks.c
+++ b/xen/xsm/flask/hooks.c
@@ -695,6 +695,7 @@ static int cf_check flask_domctl(struct domain *d, unsigned 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
     /*