[xen staging] xen/arm: process pending vPCI map/unmap operations

[patchbot@xxxxxxx]

commit c62d634cce8b1507d00a61bfc8168ac42367fe87
Author:     Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
AuthorDate: Wed Nov 24 09:59:41 2021 +0200
Commit:     Julien Grall <jgrall@xxxxxxxxxx>
CommitDate: Wed Dec 8 16:38:25 2021 +0000

    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@xxxxxxxx>
    [x86 part]
    Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>
    Reviewed-by: Paul Durrant <paul@xxxxxxx>
    Reviewed-by: Rahul Singh <rahul.singh@xxxxxxx>
    Tested-by: Rahul Singh <rahul.singh@xxxxxxx>
---
 xen/arch/arm/traps.c   | 13 +++++++++++++
 xen/arch/x86/hvm/hvm.c |  6 ++++++
 xen/common/ioreq.c     |  9 ---------
 3 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index 219ab3c3fb..8757210a79 100644
--- 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 7658f95aee..350dc396e3 100644
--- 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 d732dc045d..689d256544 100644
--- 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;
--
generated by git-patchbot for /home/xen/git/xen.git#staging