Thread (43 messages) 43 messages, 5 authors, 2013-10-25

[PATCH v8 17/19] grant-table: call set_phys_to_machine after mapping grant refs

From: Konrad Rzeszutek Wilk <hidden>
Date: 2013-10-23 14:06:27
Also in: lkml, xen-devel

On Thu, Oct 17, 2013 at 06:43:32PM +0100, Stefano Stabellini wrote:
When mapping/unmapping grant refs, call
set_phys_to_machine to update the P2M with the new mappings for
autotranslate guests.
Heh. That sounds so odd (p2m + xlat).
Can you add a sentence saying that this is a mostly a nop on x86 please?

(Well, the call to set_phys_to_machine does end up with this check:

    if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) {
                BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
                return true;
        }    
But that should be a fairly small amount of code.

quoted hunk ↗ jump to hunk
Signed-off-by: Stefano Stabellini <redacted>
---
 drivers/xen/grant-table.c |   17 +++++++++++++++--
 1 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 04cdeb8..a36cb03 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -49,6 +49,7 @@
 #include <xen/grant_table.h>
 #include <xen/interface/memory.h>
 #include <xen/hvc-console.h>
+#include <xen/swiotlb-xen.h>
 #include <asm/xen/hypercall.h>
 #include <asm/xen/interface.h>
 
@@ -889,8 +890,15 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
 			gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i,
 						&map_ops[i].status, __func__);
 
-	if (xen_feature(XENFEAT_auto_translated_physmap))
+	if (xen_feature(XENFEAT_auto_translated_physmap)) {
+		for (i = 0; i < count; i++) {
+			if (map_ops[i].status)
+				continue;
+			set_phys_to_machine(map_ops[i].host_addr >> PAGE_SHIFT,
+					map_ops[i].dev_bus_addr >> PAGE_SHIFT);
+		}
 		return ret;
+	}
 
 	if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
 		arch_enter_lazy_mmu_mode();
@@ -933,8 +941,13 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
 	if (ret)
 		return ret;
 
-	if (xen_feature(XENFEAT_auto_translated_physmap))
+	if (xen_feature(XENFEAT_auto_translated_physmap)) {
+		for (i = 0; i < count; i++) {
+			set_phys_to_machine(unmap_ops[i].host_addr >> PAGE_SHIFT,
+					INVALID_P2M_ENTRY);
+		}
 		return ret;
+	}
 
 	if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) {
 		arch_enter_lazy_mmu_mode();
-- 
1.7.2.5
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