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From: Peter Xu <peterx@redhat.com>
To: qemu-devel@nongnu.org, Stefan Hajnoczi <stefanha@redhat.com>
Cc: peterx@redhat.com, Paolo Bonzini <pbonzini@redhat.com>,
	David Hildenbrand <david@redhat.com>
Subject: [PULL 08/14] physmem: factor out direct access check into memory_region_supports_direct_access()
Date: Tue, 11 Feb 2025 17:50:52 -0500	[thread overview]
Message-ID: <20250211225059.182533-9-peterx@redhat.com> (raw)
In-Reply-To: <20250211225059.182533-1-peterx@redhat.com>

From: David Hildenbrand <david@redhat.com>

Let's factor the complete "directly accessible" check independent of
the "write" condition out so we can reuse it next.

We can now split up the checks RAM and ROMD check, so we really only check
for RAM DEVICE in case of RAM -- ROM DEVICE is neither RAM not RAM DEVICE.

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20250210084648.33798-4-david@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 include/exec/memory.h | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/include/exec/memory.h b/include/exec/memory.h
index cb35c38402..4e2cf95ab6 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -2995,10 +2995,13 @@ MemTxResult address_space_write_cached_slow(MemoryRegionCache *cache,
 int memory_access_size(MemoryRegion *mr, unsigned l, hwaddr addr);
 bool prepare_mmio_access(MemoryRegion *mr);
 
-static inline bool memory_access_is_direct(MemoryRegion *mr, bool is_write)
+static inline bool memory_region_supports_direct_access(MemoryRegion *mr)
 {
     /* ROM DEVICE regions only allow direct access if in ROMD mode. */
-    if (!memory_region_is_ram(mr) && !memory_region_is_romd(mr)) {
+    if (memory_region_is_romd(mr)) {
+        return true;
+    }
+    if (!memory_region_is_ram(mr)) {
         return false;
     }
     /*
@@ -3006,7 +3009,12 @@ static inline bool memory_access_is_direct(MemoryRegion *mr, bool is_write)
      * be MMIO and access using mempy can be wrong (e.g., using instructions not
      * intended for MMIO access). So we treat this as IO.
      */
-    if (memory_region_is_ram_device(mr)) {
+    return !memory_region_is_ram_device(mr);
+}
+
+static inline bool memory_access_is_direct(MemoryRegion *mr, bool is_write)
+{
+    if (!memory_region_supports_direct_access(mr)) {
         return false;
     }
     if (is_write) {
-- 
2.47.0



  parent reply	other threads:[~2025-02-11 22:53 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-02-11 22:50 [PULL 00/14] Mem next patches Peter Xu
2025-02-11 22:50 ` [PULL 01/14] system/physmem: take into account fd_offset for file fallocate Peter Xu
2025-02-11 22:50 ` [PULL 02/14] os: add an ability to lock memory on_fault Peter Xu
2025-02-12 14:13   ` Stefan Hajnoczi
2025-02-12 14:17     ` Daniil Tatianin
2025-02-11 22:50 ` [PULL 03/14] system/vl: extract overcommit option parsing into a helper Peter Xu
2025-02-11 22:50 ` [PULL 04/14] system: introduce a new MlockState enum Peter Xu
2025-02-11 22:50 ` [PULL 05/14] overcommit: introduce mem-lock=on-fault Peter Xu
2025-02-11 22:50 ` [PULL 06/14] physmem: factor out memory_region_is_ram_device() check in memory_access_is_direct() Peter Xu
2025-02-11 22:50 ` [PULL 07/14] physmem: factor out RAM/ROMD " Peter Xu
2025-02-11 22:50 ` Peter Xu [this message]
2025-02-11 22:50 ` [PULL 09/14] physmem: disallow direct access to RAM DEVICE in address_space_write_rom() Peter Xu
2025-02-11 22:50 ` [PULL 10/14] memory: pass MemTxAttrs to memory_access_is_direct() Peter Xu
2025-02-11 22:50 ` [PULL 11/14] hmp: use cpu_get_phys_page_debug() in hmp_gva2gpa() Peter Xu
2025-02-11 22:50 ` [PULL 12/14] physmem: teach cpu_memory_rw_debug() to write to more memory regions Peter Xu
2025-02-11 22:50 ` [PULL 13/14] system/physmem: handle hugetlb correctly in qemu_ram_remap() Peter Xu
2025-02-11 22:50 ` [PULL 14/14] system/physmem: poisoned memory discard on reboot Peter Xu

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