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From 86cb37447548420e41ff953a7372972f6154d6d1 Mon Sep 17 00:00:00 2001
From: Andrew Cooper <andrew.cooper3@citrix.com>
Date: Tue, 25 Oct 2022 09:21:11 +0000
Subject: [PATCH 27/87] arm/p2m: Rework p2m_init()
p2m_init() is mostly trivial initialisation, but has two fallible operations
which are on either side of the backpointer trigger for teardown to take
actions.
p2m_free_vmid() is idempotent with a failed p2m_alloc_vmid(), so rearrange
p2m_init() to perform all trivial setup, then set the backpointer, then
perform all fallible setup.
This will simplify a future bugfix which needs to add a third fallible
operation.
No practical change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
(cherry picked from commit: 3783e583319fa1ce75e414d851f0fde191a14753)
---
xen/arch/arm/p2m.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index b2d856a801af..4f7d923ad9f8 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -1730,7 +1730,7 @@ void p2m_final_teardown(struct domain *d)
int p2m_init(struct domain *d)
{
struct p2m_domain *p2m = p2m_get_hostp2m(d);
- int rc = 0;
+ int rc;
unsigned int cpu;
rwlock_init(&p2m->lock);
@@ -1739,11 +1739,6 @@ int p2m_init(struct domain *d)
INIT_PAGE_LIST_HEAD(&d->arch.paging.p2m_freelist);
p2m->vmid = INVALID_VMID;
-
- rc = p2m_alloc_vmid(d);
- if ( rc != 0 )
- return rc;
-
p2m->max_mapped_gfn = _gfn(0);
p2m->lowest_mapped_gfn = _gfn(ULONG_MAX);
@@ -1759,8 +1754,6 @@ int p2m_init(struct domain *d)
p2m->clean_pte = is_iommu_enabled(d) &&
!iommu_has_feature(d, IOMMU_FEAT_COHERENT_WALK);
- rc = p2m_alloc_table(d);
-
/*
* Make sure that the type chosen to is able to store the an vCPU ID
* between 0 and the maximum of virtual CPUS supported as long as
@@ -1773,13 +1766,20 @@ int p2m_init(struct domain *d)
p2m->last_vcpu_ran[cpu] = INVALID_VCPU_ID;
/*
- * Besides getting a domain when we only have the p2m in hand,
- * the back pointer to domain is also used in p2m_teardown()
- * as an end-of-initialization indicator.
+ * "Trivial" initialisation is now complete. Set the backpointer so
+ * p2m_teardown() and friends know to do something.
*/
p2m->domain = d;
- return rc;
+ rc = p2m_alloc_vmid(d);
+ if ( rc )
+ return rc;
+
+ rc = p2m_alloc_table(d);
+ if ( rc )
+ return rc;
+
+ return 0;
}
/*
--
2.37.4
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