[Minios-devel] [UNIKRAFT PATCH] plat/xen/x86: Create and initialize p2m table

[radunicolau102@xxxxxxxxx]

From: Radu Nicolau <radunicolau102@xxxxxxxxx>

Build p2m table needed for direct paging on paravirtualized Xen

Code adapted from Mini-OS.

Signed-off-by: Radu Nicolau <radunicolau102@xxxxxxxxx>
---
 plat/xen/Config.uk               |  8 +++++
 plat/xen/include/xen-arm/mm.h    |  2 ++
 plat/xen/include/xen-x86/mm_pv.h | 11 +++++--
 plat/xen/memory.c                |  8 +++++
 plat/xen/x86/mm.c                | 71 ++++++++++++++++++++++++++++++++++++++++
 5 files changed, 97 insertions(+), 3 deletions(-)

diff --git a/plat/xen/Config.uk b/plat/xen/Config.uk
index 6f6c214..18896b9 100644
--- a/plat/xen/Config.uk
+++ b/plat/xen/Config.uk
@@ -2,6 +2,7 @@ menuconfig PLAT_XEN
        bool "Xen guest image"
        default n
        depends on (ARCH_X86_32 || ARCH_X86_64 || ARCH_ARM_32)
+       imply XEN_PV_BUILD_P2M
        select LIBUKDEBUG
        select LIBNOLIBC if !HAVE_LIBC
        select LIBUKTIME if !HAVE_LIBC && ARCH_X86_64
@@ -48,6 +49,13 @@ config XEN_DEBUG_EMG_CONSOLE
                Send debug messages to the emergency console.
 endmenu
 
+config XEN_PV_BUILD_P2M
+       bool "Create p2m table"
+       default n
+       help
+               Create and initialize physical to machine (p2m) table on a PV
+               xen host
+
 config XEN_GNTTAB
        bool "Grant table support"
        default y
diff --git a/plat/xen/include/xen-arm/mm.h b/plat/xen/include/xen-arm/mm.h
index 0f5c8f5..4de76f4 100644
--- a/plat/xen/include/xen-arm/mm.h
+++ b/plat/xen/include/xen-arm/mm.h
@@ -56,4 +56,6 @@ extern uint32_t _libxenplat_paddr_offset;
 
 #define virtual_to_mfn(_virt)  virt_to_mfn(_virt)
 
+#define arch_mm_init(a)
+
 #endif
diff --git a/plat/xen/include/xen-x86/mm_pv.h b/plat/xen/include/xen-x86/mm_pv.h
index f78e62f..dc2a02e 100644
--- a/plat/xen/include/xen-x86/mm_pv.h
+++ b/plat/xen/include/xen-x86/mm_pv.h
@@ -34,6 +34,7 @@
 #define pfn_to_mfn(_pfn) (phys_to_machine_mapping[(_pfn)])
 
 /* for P2M */
+#ifdef CONFIG_XEN_PV_BUILD_P2M
 #ifdef __x86_64__
 #define P2M_SHIFT       9
 #else
@@ -49,13 +50,17 @@
 #define L3_P2M_IDX(pfn) (((pfn) >> L2_P2M_SHIFT) & P2M_MASK)
 #define INVALID_P2M_ENTRY (~0UL)
 
-void p2m_chk_pfn(unsigned long pfn);
-
 static inline unsigned long p2m_pages(unsigned long pages)
 {
        return (pages + P2M_ENTRIES - 1) >> L1_P2M_SHIFT;
 }
 
-void arch_init_p2m(unsigned long max_pfn_p);
+void arch_mm_init(struct uk_alloc *a);
+
+#ifdef CONFIG_MIGRATION
+void arch_mm_pre_suspend(void);
+void arch_mm_post_suspend(int canceled);
+#endif /* CONFIG_MIGRATION */
+#endif /* CONFIG_XEN_PV_BUILD_P2M */
 
 #endif /* _MM_PV_H */
diff --git a/plat/xen/memory.c b/plat/xen/memory.c
index 8f170dd..709c04c 100644
--- a/plat/xen/memory.c
+++ b/plat/xen/memory.c
@@ -39,8 +39,10 @@
 #include <common/gnttab.h>
 #if (defined __X86_32__) || (defined __X86_64__)
 #include <xen-x86/setup.h>
+#include <xen-x86/mm_pv.h>
 #elif (defined __ARM_32__) || (defined __ARM_64__)
 #include <xen-arm/setup.h>
+#include <xen-arm/mm.h>
 #endif
 
 #include <uk/assert.h>
@@ -141,8 +143,14 @@ int ukplat_memregion_get(int i, struct 
ukplat_memregion_desc *m)
        return 0;
 }
 
+void mm_init(void)
+{
+       arch_mm_init(ukplat_memallocator_get());
+}
+
 int _ukplat_mem_mappings_init(void)
 {
+       mm_init();
 #ifdef CONFIG_XEN_GNTTAB
        gnttab_init();
 #endif
diff --git a/plat/xen/x86/mm.c b/plat/xen/x86/mm.c
index 2f23855..dc9cc75 100644
--- a/plat/xen/x86/mm.c
+++ b/plat/xen/x86/mm.c
@@ -47,6 +47,7 @@
 #include <uk/assert.h>
 
 #ifdef CONFIG_PARAVIRT
+#include <xen-x86/mm_pv.h>
 unsigned long *phys_to_machine_mapping;
 #endif
 unsigned long mfn_zero;
@@ -684,6 +685,76 @@ void _init_mem_clear_bootstrap(void)
 #endif
 }
 
+#ifdef CONFIG_XEN_PV_BUILD_P2M
+static unsigned long max_pfn;
+static unsigned long *l3_list;
+static unsigned long *l2_list_pages[P2M_ENTRIES];
+
+void _arch_init_p2m(struct uk_alloc *a)
+{
+       unsigned long pfn;
+       unsigned long *l2_list = NULL;
+
+       max_pfn = HYPERVISOR_start_info->nr_pages;
+
+       if (((max_pfn - 1) >> L3_P2M_SHIFT) > 0)
+               UK_CRASH("Error: Too many pfns.\n");
+
+       l3_list = uk_malloc_page(a);
+       for (pfn = 0; pfn < max_pfn; pfn += P2M_ENTRIES) {
+               if (!(pfn % (P2M_ENTRIES * P2M_ENTRIES))) {
+                       l2_list = uk_malloc_page(a);
+                       l3_list[L3_P2M_IDX(pfn)] = virt_to_mfn(l2_list);
+                       l2_list_pages[L3_P2M_IDX(pfn)] = l2_list;
+               }
+
+               l2_list[L2_P2M_IDX(pfn)] =
+                       virt_to_mfn(phys_to_machine_mapping + pfn);
+       }
+       HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =
+               virt_to_mfn(l3_list);
+       HYPERVISOR_shared_info->arch.max_pfn = max_pfn;
+}
+
+void _arch_rebuild_p2m(void)
+{
+       unsigned long pfn;
+       unsigned long *l2_list = NULL;
+
+       for (pfn = 0; pfn < max_pfn; pfn += P2M_ENTRIES) {
+               if (!(pfn % (P2M_ENTRIES * P2M_ENTRIES))) {
+                       l2_list = l2_list_pages[L3_P2M_IDX(pfn)];
+                       l3_list[L3_P2M_IDX(pfn)] = virt_to_mfn(l2_list);
+               }
+
+               l2_list[L2_P2M_IDX(pfn)] =
+                               virt_to_mfn(phys_to_machine_mapping + pfn);
+       }
+       HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =
+                       virt_to_mfn(l3_list);
+       HYPERVISOR_shared_info->arch.max_pfn = max_pfn;
+}
+
+#ifdef CONFIG_MIGRATION
+void arch_mm_pre_suspend(void)
+{
+
+}
+void arch_mm_post_suspend(int canceled)
+{
+       if (!canceled)
+               arch_rebuild_p2m();
+}
+#endif
+#endif /* CONFIG_XEN_PV_BUILD_P2M */
+
+void arch_mm_init(struct uk_alloc *a)
+{
+#ifdef CONFIG_XEN_PV_BUILD_P2M
+       _arch_init_p2m(a);
+#endif
+}
+
 void _init_mem_prepare(unsigned long *start_pfn, unsigned long *max_pfn)
 {
 #ifdef CONFIG_PARAVIRT
-- 
2.7.4


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