Hello Tamas, On 28/07/2016 18:29, Tamas K Lengyel wrote:
On Thu, Jul 28, 2016 at 8:51 AM, Julien Grall <julien.gr...@arm.com> wrote:
[...]
--- xen/arch/arm/p2m.c | 18 ++++-------------- 1 file changed, 4 insertions(+), 14 deletions(-) diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c index 8676b9d..9a9c85c 100644 --- a/xen/arch/arm/p2m.c +++ b/xen/arch/arm/p2m.c @@ -398,24 +398,13 @@ out: return mfn; } -/* - * Lookup the MFN corresponding to a domain's GFN. - * - * There are no processor functions to do a stage 2 only lookup therefore we - * do a a software walk. - */ -static mfn_t __p2m_lookup(struct domain *d, gfn_t gfn, p2m_type_t *t) -{ - return p2m_get_entry(&d->arch.p2m, gfn, t, NULL, NULL); -} - mfn_t p2m_lookup(struct domain *d, gfn_t gfn, p2m_type_t *t) { mfn_t ret; struct p2m_domain *p2m = &d->arch.p2m; p2m_read_lock(p2m); - ret = __p2m_lookup(d, gfn, t); + ret = p2m_get_entry(p2m, gfn, t, NULL, NULL); p2m_read_unlock(p2m); return ret; @@ -679,7 +668,7 @@ static int __p2m_get_mem_access(struct domain *d, gfn_t gfn, * No setting was found in the Radix tree. Check if the * entry exists in the page-tables. */ - mfn_t mfn = __p2m_lookup(d, gfn, NULL); + mfn_t mfn = p2m_get_entry(p2m, gfn, NULL, NULL, NULL); if ( mfn_eq(mfn, INVALID_MFN) ) return -ESRCH; @@ -1595,6 +1584,7 @@ p2m_mem_access_check_and_get_page(vaddr_t gva, unsigned long flag) xenmem_access_t xma; p2m_type_t t; struct page_info *page = NULL; + struct p2m_domain *p2m = ¤t->domain->arch.p2m;I think this would be a good time to change this and pass p2m as an input to p2m_mem_access_check_and_get_page. This would help with our altp2m series as well.
This function can only work with the current p2m because of the call to gva_to_ipa. So I don't think it is a good idea to pass the p2m in parameter.
If you want to pass the p2m in parameter, you have to context switch properly all the registers (i.e VTTBR_EL2, TTBR{0,1}_EL1 and SCTLR_EL1).
Actually, this function is buggy if memaccess has changed the permission on memory holding the stage-1 page-table. Because we are using the hardware to translate the VA -> PA, the translate may fail due to memaccess.
Regards, -- Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
