From 22bf46f7576cc12a301d34ca743a6661afcb61ac Mon Sep 17 00:00:00 2001

From: Peter Xu <peterx@redhat.com>

Date: Fri, 12 Oct 2018 07:58:42 +0100

Subject: [PATCH 12/17] intel-iommu: introduce vtd_page_walk_info

RH-Author: Peter Xu <peterx@redhat.com>

Message-id: <20181012075846.25449-6-peterx@redhat.com>

Patchwork-id: 82678

O-Subject: [RHEL-8 qemu-kvm PATCH 5/9] intel-iommu: introduce vtd_page_walk_info

Bugzilla: 1450712

RH-Acked-by: Auger Eric <eric.auger@redhat.com>

RH-Acked-by: Xiao Wang <jasowang@redhat.com>

RH-Acked-by: Michael S. Tsirkin <mst@redhat.com>

During the recursive page walking of IOVA page tables, some stack

variables are constant variables and never changed during the whole page

walking procedure.  Isolate them into a struct so that we don't need to

pass those contants down the stack every time and multiple times.

CC: QEMU Stable <qemu-stable@nongnu.org>

Signed-off-by: Peter Xu <peterx@redhat.com>

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

(cherry picked from commit fe215b0cbb8c1f4b4af0a64aa5c02042080dd537)

Signed-off-by: Peter Xu <peterx@redhat.com>

Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>

---

 hw/i386/intel_iommu.c | 84 +++++++++++++++++++++++++++++++--------------------

 1 file changed, 52 insertions(+), 32 deletions(-)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c

index 38ccc74..e247269 100644

--- a/hw/i386/intel_iommu.c

+++ b/hw/i386/intel_iommu.c

@@ -748,9 +748,27 @@ static int vtd_iova_to_slpte(VTDContextEntry *ce, uint64_t iova, bool is_write,

 typedef int (*vtd_page_walk_hook)(IOMMUTLBEntry *entry, void *private);

+/**

+ * Constant information used during page walking

+ *

+ * @hook_fn: hook func to be called when detected page

+ * @private: private data to be passed into hook func

+ * @notify_unmap: whether we should notify invalid entries

+ * @aw: maximum address width

+ */

+typedef struct {

+    vtd_page_walk_hook hook_fn;

+    void *private;

+    bool notify_unmap;

+    uint8_t aw;

+} vtd_page_walk_info;

+

 static int vtd_page_walk_one(IOMMUTLBEntry *entry, int level,

-                             vtd_page_walk_hook hook_fn, void *private)

+                             vtd_page_walk_info *info)

 {

+    vtd_page_walk_hook hook_fn = info->hook_fn;

+    void *private = info->private;

+

     assert(hook_fn);

     trace_vtd_page_walk_one(level, entry->iova, entry->translated_addr,

                             entry->addr_mask, entry->perm);

@@ -763,17 +781,13 @@ static int vtd_page_walk_one(IOMMUTLBEntry *entry, int level,

  * @addr: base GPA addr to start the walk

  * @start: IOVA range start address

  * @end: IOVA range end address (start <= addr < end)

- * @hook_fn: hook func to be called when detected page

- * @private: private data to be passed into hook func

  * @read: whether parent level has read permission

  * @write: whether parent level has write permission

- * @notify_unmap: whether we should notify invalid entries

- * @aw: maximum address width

+ * @info: constant information for the page walk

  */

 static int vtd_page_walk_level(dma_addr_t addr, uint64_t start,

-                               uint64_t end, vtd_page_walk_hook hook_fn,

-                               void *private, uint32_t level, bool read,

-                               bool write, bool notify_unmap, uint8_t aw)

+                               uint64_t end, uint32_t level, bool read,

+                               bool write, vtd_page_walk_info *info)

 {

     bool read_cur, write_cur, entry_valid;

     uint32_t offset;

@@ -823,24 +837,24 @@ static int vtd_page_walk_level(dma_addr_t addr, uint64_t start,

         if (vtd_is_last_slpte(slpte, level)) {

             /* NOTE: this is only meaningful if entry_valid == true */

-            entry.translated_addr = vtd_get_slpte_addr(slpte, aw);

-            if (!entry_valid && !notify_unmap) {

+            entry.translated_addr = vtd_get_slpte_addr(slpte, info->aw);

+            if (!entry_valid && !info->notify_unmap) {

                 trace_vtd_page_walk_skip_perm(iova, iova_next);

                 goto next;

             }

-            ret = vtd_page_walk_one(&entry, level, hook_fn, private);

+            ret = vtd_page_walk_one(&entry, level, info);

             if (ret < 0) {

                 return ret;

             }

         } else {

             if (!entry_valid) {

-                if (notify_unmap) {

+                if (info->notify_unmap) {

                     /*

                      * The whole entry is invalid; unmap it all.

                      * Translated address is meaningless, zero it.

                      */

                     entry.translated_addr = 0x0;

-                    ret = vtd_page_walk_one(&entry, level, hook_fn, private);

+                    ret = vtd_page_walk_one(&entry, level, info);

                     if (ret < 0) {

                         return ret;

                     }

@@ -849,10 +863,9 @@ static int vtd_page_walk_level(dma_addr_t addr, uint64_t start,

                 }

                 goto next;

             }

-            ret = vtd_page_walk_level(vtd_get_slpte_addr(slpte, aw), iova,

-                                      MIN(iova_next, end), hook_fn, private,

-                                      level - 1, read_cur, write_cur,

-                                      notify_unmap, aw);

+            ret = vtd_page_walk_level(vtd_get_slpte_addr(slpte, info->aw),

+                                      iova, MIN(iova_next, end), level - 1,

+                                      read_cur, write_cur, info);

             if (ret < 0) {

                 return ret;

             }

@@ -871,28 +884,24 @@ next:

  * @ce: context entry to walk upon

  * @start: IOVA address to start the walk

  * @end: IOVA range end address (start <= addr < end)

- * @hook_fn: the hook that to be called for each detected area

- * @private: private data for the hook function

- * @aw: maximum address width

+ * @info: page walking information struct

  */

 static int vtd_page_walk(VTDContextEntry *ce, uint64_t start, uint64_t end,

-                         vtd_page_walk_hook hook_fn, void *private,

-                         bool notify_unmap, uint8_t aw)

+                         vtd_page_walk_info *info)

 {

     dma_addr_t addr = vtd_ce_get_slpt_base(ce);

     uint32_t level = vtd_ce_get_level(ce);

-    if (!vtd_iova_range_check(start, ce, aw)) {

+    if (!vtd_iova_range_check(start, ce, info->aw)) {

         return -VTD_FR_ADDR_BEYOND_MGAW;

     }

-    if (!vtd_iova_range_check(end, ce, aw)) {

+    if (!vtd_iova_range_check(end, ce, info->aw)) {

         /* Fix end so that it reaches the maximum */

-        end = vtd_iova_limit(ce, aw);

+        end = vtd_iova_limit(ce, info->aw);

     }

-    return vtd_page_walk_level(addr, start, end, hook_fn, private,

-                               level, true, true, notify_unmap, aw);

+    return vtd_page_walk_level(addr, start, end, level, true, true, info);

 }

 /* Map a device to its corresponding domain (context-entry) */

@@ -1449,14 +1458,19 @@ static void vtd_iotlb_page_invalidate_notify(IntelIOMMUState *s,

                                        vtd_as->devfn, &ce);

         if (!ret && domain_id == VTD_CONTEXT_ENTRY_DID(ce.hi)) {

             if (vtd_as_has_map_notifier(vtd_as)) {

+                vtd_page_walk_info info = {

+                    .hook_fn = vtd_page_invalidate_notify_hook,

+                    .private = (void *)&vtd_as->iommu,

+                    .notify_unmap = true,

+                    .aw = s->aw_bits,

+                };

+

                 /*

                  * As long as we have MAP notifications registered in

                  * any of our IOMMU notifiers, we need to sync the

                  * shadow page table.

                  */

-                vtd_page_walk(&ce, addr, addr + size,

-                              vtd_page_invalidate_notify_hook,

-                              (void *)&vtd_as->iommu, true, s->aw_bits);

+                vtd_page_walk(&ce, addr, addr + size, &info;;

             } else {

                 /*

                  * For UNMAP-only notifiers, we don't need to walk the

@@ -2924,8 +2938,14 @@ static void vtd_iommu_replay(IOMMUMemoryRegion *iommu_mr, IOMMUNotifier *n)

                                   ce.hi, ce.lo);

         if (vtd_as_has_map_notifier(vtd_as)) {

             /* This is required only for MAP typed notifiers */

-            vtd_page_walk(&ce, 0, ~0ULL, vtd_replay_hook, (void *)n, false,

-                          s->aw_bits);

+            vtd_page_walk_info info = {

+                .hook_fn = vtd_replay_hook,

+                .private = (void *)n,

+                .notify_unmap = false,

+                .aw = s->aw_bits,

+            };

+

+            vtd_page_walk(&ce, 0, ~0ULL, &info;;

         }

     } else {

         trace_vtd_replay_ce_invalid(bus_n, PCI_SLOT(vtd_as->devfn),

-- 

1.8.3.1