From: Roger Pau Monne <roger.pau@citrix.com>
To: xen-devel@lists.xenproject.org
Cc: Roger Pau Monne <roger.pau@citrix.com>,
Shawn Anastasio <sanastasio@raptorengineering.com>,
Alistair Francis <alistair.francis@wdc.com>,
Bob Eshleman <bobbyeshleman@gmail.com>,
Connor Davis <connojdavis@gmail.com>,
Oleksii Kurochko <oleksii.kurochko@gmail.com>
Subject: [PATCH for-4.19] ppc/riscv: fix arch_acquire_resource_check()
Date: Tue, 30 Apr 2024 17:34:23 +0200 [thread overview]
Message-ID: <20240430153423.80875-1-roger.pau@citrix.com> (raw)
None of the implementations support set_foreign_p2m_entry() yet, neither they
have a p2m walk in domain_relinquish_resources() in order to remove the foreign
mappings from the p2m and thus drop the extra refcounts.
Adjust the arch helpers to return false and introduce a comment that clearly
states it is not only taking extra refcounts that's needed, but also dropping
them on domain teardown.
Fixes: 4988704e00d8 ('xen/riscv: introduce p2m.h')
Fixes: 4a2f68f90930 ('xen/ppc: Define minimal stub headers required for full build')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
xen/arch/ppc/include/asm/p2m.h | 7 ++++---
xen/arch/riscv/include/asm/p2m.h | 7 ++++---
2 files changed, 8 insertions(+), 6 deletions(-)
diff --git a/xen/arch/ppc/include/asm/p2m.h b/xen/arch/ppc/include/asm/p2m.h
index 25ba05466853..f144ef8e1a54 100644
--- a/xen/arch/ppc/include/asm/p2m.h
+++ b/xen/arch/ppc/include/asm/p2m.h
@@ -81,10 +81,11 @@ static inline mfn_t gfn_to_mfn(struct domain *d, gfn_t gfn)
static inline bool arch_acquire_resource_check(struct domain *d)
{
/*
- * The reference counting of foreign entries in set_foreign_p2m_entry()
- * is supported on PPC.
+ * Requires refcounting the foreign mappings and walking the p2m on
+ * teardown in order to remove foreign pages from the p2m and drop the
+ * extra reference counts.
*/
- return true;
+ return false;
}
static inline void p2m_altp2m_check(struct vcpu *v, uint16_t idx)
diff --git a/xen/arch/riscv/include/asm/p2m.h b/xen/arch/riscv/include/asm/p2m.h
index 87b13f897926..387f372b5d26 100644
--- a/xen/arch/riscv/include/asm/p2m.h
+++ b/xen/arch/riscv/include/asm/p2m.h
@@ -79,10 +79,11 @@ static inline mfn_t gfn_to_mfn(struct domain *d, gfn_t gfn)
static inline bool arch_acquire_resource_check(struct domain *d)
{
/*
- * The reference counting of foreign entries in set_foreign_p2m_entry()
- * is supported on RISCV.
+ * Requires refcounting the foreign mappings and walking the p2m on
+ * teardown in order to remove foreign pages from the p2m and drop the
+ * extra reference counts.
*/
- return true;
+ return false;
}
static inline void p2m_altp2m_check(struct vcpu *v, uint16_t idx)
--
2.44.0
next reply other threads:[~2024-04-30 15:34 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-30 15:34 Roger Pau Monne [this message]
2024-05-02 7:23 ` [PATCH for-4.19] ppc/riscv: fix arch_acquire_resource_check() Jan Beulich
2024-05-02 7:35 ` Roger Pau Monné
2024-05-02 8:46 ` Oleksii
2024-05-02 10:31 ` Roger Pau Monné
2024-05-05 22:12 ` Shawn Anastasio
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