From c93e9e412440e1acaace9a4c2ec2c3c2a55ba0af Mon Sep 17 00:00:00 2001 From: Julien Grall Date: Tue, 22 Apr 2014 14:14:18 +0100 Subject: [PATCH] xen/arm: p2m: apply_p2m_changes: Only load domain P2M when we flush TLBs apply_p2m_changes needs to switch to another VTTBR temporarily to avoid flush every TLBs. As it's only needed there, we can restrict the scope where the VTTBR of this domain is loaded. Signed-off-by: Julien Grall Acked-by: Ian Campbell --- xen/arch/arm/p2m.c | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c index 0730da4b09..603c097bd7 100644 --- a/xen/arch/arm/p2m.c +++ b/xen/arch/arm/p2m.c @@ -296,9 +296,6 @@ static int apply_p2m_changes(struct domain *d, spin_lock(&p2m->lock); - if ( d != current->domain ) - p2m_load_VTTBR(d); - addr = start_gpaddr; while ( addr < end_gpaddr ) { @@ -454,12 +451,17 @@ static int apply_p2m_changes(struct domain *d, if ( flush ) { - /* At the beginning of the function, Xen is updating VTTBR - * with the domain where the mappings are created. In this - * case it's only necessary to flush TLBs on every CPUs with - * the current VMID (our domain). + /* Update the VTTBR if necessary with the domain where mappings + * are created. In this case it's only necessary to flush TLBs + * on every CPUs with the current VMID (our domain). */ + if ( d != current->domain ) + p2m_load_VTTBR(d); + flush_tlb(); + + if ( d != current->domain ) + p2m_load_VTTBR(current->domain); } if ( op == ALLOCATE || op == INSERT ) @@ -478,9 +480,6 @@ out: if (second) unmap_domain_page(second); if (first) unmap_domain_page(first); - if ( d != current->domain ) - p2m_load_VTTBR(current->domain); - spin_unlock(&p2m->lock); return rc; -- 2.30.2