[PATCH v2] hvf: Avoid mapping regions < PAGE_SIZE as ram

Alexander Graf posted 1 patch 2 years, 6 months ago
Test checkpatch passed
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/qemu tags/patchew/20211025132147.28308-1-agraf@csgraf.de
Maintainers: Cameron Esfahani <dirty@apple.com>, Roman Bolshakov <r.bolshakov@yadro.com>
accel/hvf/hvf-accel-ops.c | 7 +++++++
1 file changed, 7 insertions(+)
[PATCH v2] hvf: Avoid mapping regions < PAGE_SIZE as ram
Posted by Alexander Graf 2 years, 6 months ago
HVF has generic memory listener code that adds all RAM regions as HVF RAM
regions. However, HVF can only handle page aligned, page granule regions.

So let's ignore regions that are not page aligned and sized. They will be
trapped as MMIO instead.

Signed-off-by: Alexander Graf <agraf@csgraf.de>

---

v1 -> v2:

  - Use QEMU_IS_ALIGNED()
---
 accel/hvf/hvf-accel-ops.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/accel/hvf/hvf-accel-ops.c b/accel/hvf/hvf-accel-ops.c
index 2b2c411076..54457c76c2 100644
--- a/accel/hvf/hvf-accel-ops.c
+++ b/accel/hvf/hvf-accel-ops.c
@@ -122,6 +122,7 @@ static void hvf_set_phys_mem(MemoryRegionSection *section, bool add)
     MemoryRegion *area = section->mr;
     bool writeable = !area->readonly && !area->rom_device;
     hv_memory_flags_t flags;
+    uint64_t page_size = qemu_real_host_page_size;
 
     if (!memory_region_is_ram(area)) {
         if (writeable) {
@@ -135,6 +136,12 @@ static void hvf_set_phys_mem(MemoryRegionSection *section, bool add)
         }
     }
 
+    if (!QEMU_IS_ALIGNED(int128_get64(section->size), page_size) ||
+        !QEMU_IS_ALIGNED(section->offset_within_address_space, page_size)) {
+        /* Not page aligned, so we can not map as RAM */
+        add = false;
+    }
+
     mem = hvf_find_overlap_slot(
             section->offset_within_address_space,
             int128_get64(section->size));
-- 
2.30.1 (Apple Git-130)


Re: [PATCH v2] hvf: Avoid mapping regions < PAGE_SIZE as ram
Posted by Philippe Mathieu-Daudé 2 years, 6 months ago
On 10/25/21 15:21, Alexander Graf wrote:
> HVF has generic memory listener code that adds all RAM regions as HVF RAM
> regions. However, HVF can only handle page aligned, page granule regions.
> 
> So let's ignore regions that are not page aligned and sized. They will be
> trapped as MMIO instead.
> 
> Signed-off-by: Alexander Graf <agraf@csgraf.de>
> 
> ---
> 
> v1 -> v2:
> 
>   - Use QEMU_IS_ALIGNED()
> ---
>  accel/hvf/hvf-accel-ops.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/accel/hvf/hvf-accel-ops.c b/accel/hvf/hvf-accel-ops.c
> index 2b2c411076..54457c76c2 100644
> --- a/accel/hvf/hvf-accel-ops.c
> +++ b/accel/hvf/hvf-accel-ops.c
> @@ -122,6 +122,7 @@ static void hvf_set_phys_mem(MemoryRegionSection *section, bool add)
>      MemoryRegion *area = section->mr;
>      bool writeable = !area->readonly && !area->rom_device;
>      hv_memory_flags_t flags;
> +    uint64_t page_size = qemu_real_host_page_size;
>  
>      if (!memory_region_is_ram(area)) {
>          if (writeable) {
> @@ -135,6 +136,12 @@ static void hvf_set_phys_mem(MemoryRegionSection *section, bool add)
>          }
>      }
>  
> +    if (!QEMU_IS_ALIGNED(int128_get64(section->size), page_size) ||
> +        !QEMU_IS_ALIGNED(section->offset_within_address_space, page_size)) {
> +        /* Not page aligned, so we can not map as RAM */
> +        add = false;
> +    }
> +
>      mem = hvf_find_overlap_slot(
>              section->offset_within_address_space,
>              int128_get64(section->size));
> 

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>