From: Julien Grall <jgr...@amazon.com>
PMAP will be used in a follow-up patch to bootstrap map domain
page infrastructure -- we need some way to map pages to setup the
mapcache without a direct map.
The functions pmap_{map, unmap} open code {set, clear}_fixmap to break
the loop.
Signed-off-by: Julien Grall <jgr...@amazon.com>
Signed-off-by: Elias El Yandouzi <elias...@amazon.com>
----
The PMAP infrastructure was upstream separately for Arm since
Hongyan sent the secret-free hypervisor series. So this is a new
patch to plumb the feature on x86.
Changes in v2:
* Declare PMAP entries earlier in fixed_addresses
* Reword the commit message
diff --git a/xen/arch/x86/Kconfig b/xen/arch/x86/Kconfig
index b4ec0e582e..56feb0c564 100644
--- a/xen/arch/x86/Kconfig
+++ b/xen/arch/x86/Kconfig
@@ -27,6 +27,7 @@ config X86
select HAS_PCI
select HAS_PCI_MSI
select HAS_PIRQ
+ select HAS_PMAP
select HAS_SCHED_GRANULARITY
select HAS_SECRET_HIDING
select HAS_UBSAN
diff --git a/xen/arch/x86/include/asm/fixmap.h
b/xen/arch/x86/include/asm/fixmap.h
index 516ec3fa6c..a7ac365fc6 100644
--- a/xen/arch/x86/include/asm/fixmap.h
+++ b/xen/arch/x86/include/asm/fixmap.h
@@ -21,6 +21,8 @@
#include <xen/acpi.h>
#include <xen/pfn.h>
+#include <xen/pmap.h>
+
#include <asm/apicdef.h>
#include <asm/msi.h>
#include <acpi/apei.h>
@@ -53,6 +55,8 @@ enum fixed_addresses {
FIX_PV_CONSOLE,
FIX_XEN_SHARED_INFO,
#endif /* CONFIG_XEN_GUEST */
+ FIX_PMAP_BEGIN,
+ FIX_PMAP_END = FIX_PMAP_BEGIN + NUM_FIX_PMAP,
/* Everything else should go further down. */
FIX_APIC_BASE,
FIX_IO_APIC_BASE_0,
diff --git a/xen/arch/x86/include/asm/pmap.h b/xen/arch/x86/include/asm/pmap.h
new file mode 100644
index 0000000000..62746e191d
--- /dev/null
+++ b/xen/arch/x86/include/asm/pmap.h
@@ -0,0 +1,25 @@
+#ifndef __ASM_PMAP_H__
+#define __ASM_PMAP_H__
+
+#include <asm/fixmap.h>
+
+static inline void arch_pmap_map(unsigned int slot, mfn_t mfn)
+{
+ unsigned long linear = (unsigned long)fix_to_virt(slot);
+ l1_pgentry_t *pl1e = &l1_fixmap[l1_table_offset(linear)];
+
+ ASSERT(!(l1e_get_flags(*pl1e) & _PAGE_PRESENT));
+
+ l1e_write_atomic(pl1e, l1e_from_mfn(mfn, PAGE_HYPERVISOR));
+}
+
+static inline void arch_pmap_unmap(unsigned int slot)
+{
+ unsigned long linear = (unsigned long)fix_to_virt(slot);
+ l1_pgentry_t *pl1e = &l1_fixmap[l1_table_offset(linear)];
+
+ l1e_write_atomic(pl1e, l1e_empty());
+ flush_tlb_one_local(linear);
+}
+
+#endif /* __ASM_PMAP_H__ */
--
2.40.1
