xen/arm: process pending vPCI map/unmap operations

vPCI may map and unmap PCI device memory (BARs) being passed through which
may take a lot of time. For this those operations may be deferred to be
performed later, so that they can be safely preempted.

Currently this deferred processing is happening in common IOREQ code
which doesn't seem to be the right place for x86 and is even more
doubtful because IOREQ may not be enabled for Arm at all.
So, for Arm the pending vPCI work may have no chance to be executed
if the processing is left as is in the common IOREQ code only.
For that reason make vPCI processing happen in arch specific code.

Please be aware that there are a few outstanding TODOs affecting this
code path, see xen/drivers/vpci/header.c:map_range and
xen/drivers/vpci/header.c:vpci_process_pending.

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
[x86 part]
Acked-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Rahul Singh <rahul.singh@arm.com>
Tested-by: Rahul Singh <rahul.singh@arm.com>

diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index 219ab3c3fbdefa847a3d6fd7e3017b7080dcf363..8757210a798bf71f5a81cee09a4460b59b933878 100644 (file)
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -34,6 +34,7 @@
 #include <xen/symbols.h>
 #include <xen/version.h>
 #include <xen/virtual_region.h>
+#include <xen/vpci.h>
 
 #include <public/sched.h>
 #include <public/xen.h>
@@ -2290,6 +2291,18 @@ static bool check_for_vcpu_work(void)
 {
     struct vcpu *v = current;
 
+    if ( has_vpci(v->domain) )
+    {
+        bool pending;
+
+        local_irq_enable();
+        pending = vpci_process_pending(v);
+        local_irq_disable();
+
+        if ( pending )
+            return true;
+    }
+
 #ifdef CONFIG_IOREQ_SERVER
     if ( domain_has_ioreq_server(v->domain) )
     {

diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 7658f95aeeb474b44262800ebc63522eb36f9959..350dc396e37cdd9d57c49fdaf1e8324323d6ca4c 100644 (file)
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -546,6 +546,12 @@ void hvm_do_resume(struct vcpu *v)
 
     pt_restore_timer(v);
 
+    if ( has_vpci(v->domain) && vpci_process_pending(v) )
+    {
+        raise_softirq(SCHEDULE_SOFTIRQ);
+        return;
+    }
+
     if ( !vcpu_ioreq_handle_completion(v) )
         return;
 

diff --git a/xen/common/ioreq.c b/xen/common/ioreq.c
index d732dc045df9911e90aa26b189c64b6b810d40e5..689d256544c8064dcd9b0d779e07cf80329bcac0 100644 (file)
--- a/xen/common/ioreq.c
+++ b/xen/common/ioreq.c
@@ -25,9 +25,7 @@
 #include <xen/lib.h>
 #include <xen/paging.h>
 #include <xen/sched.h>
-#include <xen/softirq.h>
 #include <xen/trace.h>
-#include <xen/vpci.h>
 
 #include <asm/guest_atomics.h>
 #include <asm/ioreq.h>
@@ -212,19 +210,12 @@ static bool wait_for_io(struct ioreq_vcpu *sv, ioreq_t *p)
 
 bool vcpu_ioreq_handle_completion(struct vcpu *v)
 {
-    struct domain *d = v->domain;
     struct vcpu_io *vio = &v->io;
     struct ioreq_server *s;
     struct ioreq_vcpu *sv;
     enum vio_completion completion;
     bool res = true;
 
-    if ( has_vpci(d) && vpci_process_pending(v) )
-    {
-        raise_softirq(SCHEDULE_SOFTIRQ);
-        return false;
-    }
-
     while ( (sv = get_pending_vcpu(v, &s)) != NULL )
         if ( !wait_for_io(sv, get_ioreq(s, v)) )
             return false;