[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v2] xsm: add device tree labeling support
Hi Jan, On 13/03/2015 09:23, Jan Beulich wrote: On 12.03.15 at 21:42, <dgdegra@xxxxxxxxxxxxx> wrote:@@ -1999,11 +2055,23 @@ int policydb_read(struct policydb *p, void *fp) "Old xen policy does not support iomemcon"); goto bad; } - rc = next_entry(buf, fp, sizeof(u32) *2); - if ( rc < 0 ) - goto bad; - c->u.iomem.low_iomem = le32_to_cpu(buf[0]); - c->u.iomem.high_iomem = le32_to_cpu(buf[1]); + if ( p->policyvers >= POLICYDB_VERSION_XEN_DEVICETREE ) + { + u64 b64[2]; + rc = next_entry(b64, fp, sizeof(u64) *2); + if ( rc < 0 ) + goto bad; + c->u.iomem.low_iomem = le64_to_cpu(b64[0]); + c->u.iomem.high_iomem = le64_to_cpu(b64[1]); + } + else + { + rc = next_entry(buf, fp, sizeof(u32) *2); + if ( rc < 0 ) + goto bad; + c->u.iomem.low_iomem = le32_to_cpu(buf[0]); + c->u.iomem.high_iomem = le32_to_cpu(buf[1]); + }I might be completely wrong (knowing next to nothing about XSM), but how is the permissible I/O mem range tied to DT (as expressed by POLICYDB_VERSION_XEN_DEVICETREE)? All systems with valid page frame number possibly being wider than 32 bits would need this extension, i.e. namely also x86. I guess the name POLICYDB_VERSION_XEN_DEVICETREE was arbitrarily chose. The policy version 30 adds support for both device tree and 64 bits iomem.Although, I'm wondering if we should deny policy < 30 on newer Xen because a truncation on the MMIO pfns may occurs and give access to the wrong pfn. Regards, -- Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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