An error message can seen from the init-dom0less application on
direct-mapped 1:1 domains:
```
Allocating magic pages
memory.c:238:d0v0 mfn 0x39000 doesn't belong to d1
Error on alloc magic pages
```
This is because populate_physmap() automatically assumes gfn == mfn
for direct mapped domains. This cannot be true for the magic pages
that are allocated later for Dom0less DomUs from the init-dom0less
helper application executed in Dom0.
Force populate_physmap to take the "normal" memory allocation route for
the magic pages even for 1:1 Dom0less DomUs. This should work as long
as the 1:1 Dom0less DomU doesn't have anything else mapped at the same
guest address as the magic pages:
- gfn 0x39000 address 0x39000000
- gfn 0x39001 address 0x39001000
- gfn 0x39002 address 0x39002000
- gfn 0x39003 address 0x39003000
Create helper is_magic_gpfn() for Arm to assist this and stub helpers
for non-Arm architectures to avoid #ifdef. Move the definition of the
magic pages on Arm to a more common place.
Note that the init-dom0less application of the diffenent Xen version
may allocate all or part of four magic pages for each DomU.
Reported-by: Alec Kwapis <alec.kwa...@medtronic.com>
Signed-off-by: Stefano Stabellini <sstabell...@kernel.org>
Signed-off-by: Henry Wang <xin.wa...@amd.com>
---
tools/libs/guest/xg_dom_arm.c | 6 ------
xen/arch/arm/include/asm/mm.h | 13 +++++++++++++
xen/arch/ppc/include/asm/mm.h | 5 +++++
xen/arch/riscv/include/asm/mm.h | 6 ++++++
xen/arch/x86/include/asm/mm.h | 5 +++++
xen/common/memory.c | 2 +-
xen/include/public/arch-arm.h | 6 ++++++
7 files changed, 36 insertions(+), 7 deletions(-)
diff --git a/tools/libs/guest/xg_dom_arm.c b/tools/libs/guest/xg_dom_arm.c
index 2fd8ee7ad4..8c579d7576 100644
--- a/tools/libs/guest/xg_dom_arm.c
+++ b/tools/libs/guest/xg_dom_arm.c
@@ -25,12 +25,6 @@
#include "xg_private.h"
-#define NR_MAGIC_PAGES 4
-#define CONSOLE_PFN_OFFSET 0
-#define XENSTORE_PFN_OFFSET 1
-#define MEMACCESS_PFN_OFFSET 2
-#define VUART_PFN_OFFSET 3
-
#define LPAE_SHIFT 9
#define PFN_4K_SHIFT (0)
diff --git a/xen/arch/arm/include/asm/mm.h b/xen/arch/arm/include/asm/mm.h
index cbcf3bf147..17149b4635 100644
--- a/xen/arch/arm/include/asm/mm.h
+++ b/xen/arch/arm/include/asm/mm.h
@@ -428,6 +428,19 @@ static inline void page_set_xenheap_gfn(struct page_info
*p, gfn_t gfn)
} while ( (y = cmpxchg(&p->u.inuse.type_info, x, nx)) != x );
}
+#define MAGIC_PAGE_N_GPFN(n) ((GUEST_MAGIC_BASE >> PAGE_SHIFT) + n)
+static inline bool is_magic_gpfn(xen_pfn_t gpfn)
+{
+ unsigned int i;
+ for ( i = 0; i < NR_MAGIC_PAGES; i++ )
+ {
+ if ( gpfn == MAGIC_PAGE_N_GPFN(i) )
+ return true;
+ }
+
+ return false;
+}
+
#endif /* __ARCH_ARM_MM__ */
/*
* Local variables:
diff --git a/xen/arch/ppc/include/asm/mm.h b/xen/arch/ppc/include/asm/mm.h
index a433936076..8ad81d9552 100644
--- a/xen/arch/ppc/include/asm/mm.h
+++ b/xen/arch/ppc/include/asm/mm.h
@@ -256,4 +256,9 @@ static inline bool arch_mfns_in_directmap(unsigned long
mfn, unsigned long nr)
return true;
}
+static inline bool is_magic_gpfn(xen_pfn_t gpfn)
+{
+ return false;
+}
+
#endif /* _ASM_PPC_MM_H */
diff --git a/xen/arch/riscv/include/asm/mm.h b/xen/arch/riscv/include/asm/mm.h
index 07c7a0abba..a376a77e29 100644
--- a/xen/arch/riscv/include/asm/mm.h
+++ b/xen/arch/riscv/include/asm/mm.h
@@ -3,6 +3,7 @@
#ifndef _ASM_RISCV_MM_H
#define _ASM_RISCV_MM_H
+#include <public/xen.h>
#include <asm/page-bits.h>
#define pfn_to_paddr(pfn) ((paddr_t)(pfn) << PAGE_SHIFT)
@@ -20,4 +21,9 @@ unsigned long calc_phys_offset(void);
void turn_on_mmu(unsigned long ra);
+static inline bool is_magic_gpfn(xen_pfn_t gpfn)
+{
+ return false;
+}
+
#endif /* _ASM_RISCV_MM_H */
diff --git a/xen/arch/x86/include/asm/mm.h b/xen/arch/x86/include/asm/mm.h
index 7d26d9cd2f..f385f36d78 100644
--- a/xen/arch/x86/include/asm/mm.h
+++ b/xen/arch/x86/include/asm/mm.h
@@ -628,4 +628,9 @@ static inline bool arch_mfns_in_directmap(unsigned long
mfn, unsigned long nr)
return (mfn + nr) <= (virt_to_mfn(eva - 1) + 1);
}
+static inline bool is_magic_gpfn(xen_pfn_t gpfn)
+{
+ return false;
+}
+
#endif /* __ASM_X86_MM_H__ */
diff --git a/xen/common/memory.c b/xen/common/memory.c
index b3b05c2ec0..ab4bad79e2 100644
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -219,7 +219,7 @@ static void populate_physmap(struct memop_args *a)
}
else
{
- if ( is_domain_direct_mapped(d) )
+ if ( is_domain_direct_mapped(d) && !is_magic_gpfn(gpfn) )
{
mfn = _mfn(gpfn);
diff --git a/xen/include/public/arch-arm.h b/xen/include/public/arch-arm.h
index a25e87dbda..58aa6ff05b 100644
--- a/xen/include/public/arch-arm.h
+++ b/xen/include/public/arch-arm.h
@@ -476,6 +476,12 @@ typedef uint64_t xen_callback_t;
#define GUEST_MAGIC_BASE xen_mk_ullong(0x39000000)
#define GUEST_MAGIC_SIZE xen_mk_ullong(0x01000000)
+#define NR_MAGIC_PAGES 4
+#define CONSOLE_PFN_OFFSET 0
+#define XENSTORE_PFN_OFFSET 1
+#define MEMACCESS_PFN_OFFSET 2
+#define VUART_PFN_OFFSET 3
+
#define GUEST_RAM_BANKS 2
/*
--
2.34.1
