[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v1 1/1] xen/arm: Relax hw domain mapping attributes to p2m_mmio_direct_c
On Thu, Jan 19, 2017 at 12:40:45PM +0000, Julien Grall wrote: > Hi Edgar, Hi Julien, > > On 10/01/2017 11:37, Edgar E. Iglesias wrote: > >From: "Edgar E. Iglesias" <edgar.iglesias@xxxxxxxxxx> > > > >Relax the hardware domains mapping attributes to p2m_mmio_direct_c. > >This will allow the hardware domain to fully control the > >attribtues via its S1 mappings. > > s/attribtues/attributes/ Fixed for v2. > > I would like some rationale in the commit message to explain why it is fine > to do this relaxation (e.g the hardware domain is a trusted domain). I've added the following for v2: Since the hardware domain is a trusted domain, we extend the trust to include making final decisions on what attributes to use when mapping memory regions. For device-tree configured hardware domains, this patch relaxes the hardware domains mapping attributes to p2m_mmio_direct_c. This will allow the hardware domain to control the attributes via its S1 mappings. > > A such relaxation would probably be necessary for the ACPI case too (see > map_dev_mmio_region). I don't have testcases for ACPI but I'll try to fix it. Please correct me if I'm wrong. IIUC, when using ACPI, we map in a few selected devices (UART, GIC, SMMU, RAM) to dom0 but leave the rest unmapped. Dom0 then parses ACPI tables and issues hypervisor calls to map individual devices (XENMEM_add_to_physmap with XENMAPSPACE_dev_mmio). Since XENMEM_add_to_physmap with XENMAPSPACE_dev_mmio is only used for dom0 mappings, I think this relaxation would be safe: +++ b/xen/arch/arm/p2m.c @@ -1185,7 +1185,7 @@ int map_dev_mmio_region(struct domain *d, if ( !(nr && iomem_access_permitted(d, mfn_x(mfn), mfn_x(mfn) + nr - 1)) ) return 0; - res = map_mmio_regions(d, gfn, nr, mfn); + res = p2m_insert_mapping(d, gfn, nr, mfn, p2m_mmio_direct_c); if ( res < 0 ) { Anyway, I'll send the v2 series out and we can discuss from there. > Also, this is a revert of patch 1e75ed8 and 9eed361 + relaxation, I would > either mention it in the commit message. Or send separate patch to revert > both of them. Either way will be fine by me. I've changed v2 to keep the plumbing but revert 9eed361. Thanks, Edgar > > > > >Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xxxxxxxxxx> > >--- > > xen/arch/arm/domain_build.c | 63 > > ++++++++++----------------------------------- > > 1 file changed, 13 insertions(+), 50 deletions(-) > > > >diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c > >index 07b868d..a3521c7 100644 > >--- a/xen/arch/arm/domain_build.c > >+++ b/xen/arch/arm/domain_build.c > >@@ -48,20 +48,6 @@ struct map_range_data > > p2m_type_t p2mt; > > }; > > > >-static const struct dt_device_match dev_map_attrs[] __initconst = > >-{ > >- { > >- __DT_MATCH_COMPATIBLE("mmio-sram"), > >- __DT_MATCH_PROP("no-memory-wc"), > >- .data = (void *) (uintptr_t) p2m_mmio_direct_dev, > >- }, > >- { > >- __DT_MATCH_COMPATIBLE("mmio-sram"), > >- .data = (void *) (uintptr_t) p2m_mmio_direct_nc, > >- }, > >- { /* sentinel */ }, > >-}; > >- > > //#define DEBUG_11_ALLOCATION > > #ifdef DEBUG_11_ALLOCATION > > # define D11PRINT(fmt, args...) printk(XENLOG_DEBUG fmt, ##args) > >@@ -1005,8 +991,7 @@ static int map_range_to_domain(const struct > >dt_device_node *dev, > > u64 addr, u64 len, > > void *data) > > { > >- struct map_range_data *mr_data = data; > > I would actually prefer to keep the plumbing and only remove dev_map_attrs. > Stefano do you have any opinions? > > If we are going to remove the plumbing, you would need to remove > map_range_data which has been introduced by the plumbing patch. > > Cheers, > > -- > Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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