[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH 1/6] xen: extend XEN_DOMCTL_memory_mapping to handle cacheability



Hi Stefano,

On 2/26/19 11:07 PM, Stefano Stabellini wrote:
Reuse the existing padding field to pass cacheability information about
the memory mapping, specifically, whether the memory should be mapped as
normal memory or as device memory (this is what we have today).

Add a cacheability parameter to map_mmio_regions. 0 means device
memory, which is what we have today.

On ARM, map device memory as p2m_mmio_direct_dev (as it is already done
today) and normal memory as p2m_ram_rw.

On x86, return error if the cacheability requested is not device memory.

Signed-off-by: Stefano Stabellini <stefanos@xxxxxxxxxx>
CC: JBeulich@xxxxxxxx
CC: andrew.cooper3@xxxxxxxxxx
---
  xen/arch/arm/gic-v2.c            |  3 ++-
  xen/arch/arm/p2m.c               | 19 +++++++++++++++++--
  xen/arch/arm/platforms/exynos5.c |  4 ++--
  xen/arch/arm/platforms/omap5.c   |  8 ++++----
  xen/arch/arm/vgic-v2.c           |  2 +-
  xen/arch/arm/vgic/vgic-v2.c      |  2 +-
  xen/arch/x86/hvm/dom0_build.c    |  7 +++++--
  xen/arch/x86/mm/p2m.c            |  6 +++++-
  xen/common/domctl.c              |  8 +++++---
  xen/drivers/vpci/header.c        |  3 ++-
  xen/include/public/domctl.h      |  4 +++-
  xen/include/xen/p2m-common.h     |  3 ++-
  12 files changed, 49 insertions(+), 20 deletions(-)

diff --git a/xen/arch/arm/gic-v2.c b/xen/arch/arm/gic-v2.c
index e7eb01f..1ea3da2 100644
--- a/xen/arch/arm/gic-v2.c
+++ b/xen/arch/arm/gic-v2.c
@@ -690,7 +690,8 @@ static int gicv2_map_hwdown_extra_mappings(struct domain *d)
ret = map_mmio_regions(d, gaddr_to_gfn(v2m_data->addr),
                                 PFN_UP(v2m_data->size),
-                               maddr_to_mfn(v2m_data->addr));
+                               maddr_to_mfn(v2m_data->addr),
+                               CACHEABILITY_DEVMEM);
          if ( ret )
          {
              printk(XENLOG_ERR "GICv2: Map v2m frame to d%d failed.\n",
diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index 30cfb01..5b8fcc5 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -1068,9 +1068,24 @@ int unmap_regions_p2mt(struct domain *d,
  int map_mmio_regions(struct domain *d,
                       gfn_t start_gfn,
                       unsigned long nr,
-                     mfn_t mfn)
+                     mfn_t mfn,
+                     uint32_t cache_policy)

Rather than extending map_mmio_regions, I would prefer if we kill this function (and unmap_mmio_mmio_regions) and instead use map_regions_p2mt.

This means the conversation to p2mt should be done in the DOMCTL handling.

  {
-    return p2m_insert_mapping(d, start_gfn, nr, mfn, p2m_mmio_direct_dev);
+    p2m_type_t t;
+
+    switch ( cache_policy )
+    {
+    case CACHEABILITY_MEMORY:
+        t = p2m_ram_rw;
+        break;
+    case CACHEABILITY_DEVMEM:
+        t = p2m_mmio_direct_dev;
+        break;
+    default:
+        return -ENOSYS;

We tend to use EOPNOTSUPP in such a case.

Cheers,

--
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.