[PATCH v1 6/6] xen/riscv: enable DOMAIN_BUILD_HELPERS

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

To enable DOMAIN_BUILD_HELPERS for RISC-V the following is introduced:
- Add a global p2m_ipa_bits variable, initialized to PADDR_BITS, to
  represent the maximum supported IPA size as find_unallocated_memory()
  requires it.
- Define default guest RAM layout parameters in the public RISC-V
  header as it is required by allocate_memory().

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
---
 xen/arch/riscv/Kconfig           | 1 +
 xen/arch/riscv/include/asm/p2m.h | 3 +++
 xen/arch/riscv/p2m.c             | 6 ++++++
 xen/include/public/arch-riscv.h  | 8 ++++++++
 4 files changed, 18 insertions(+)

diff --git a/xen/arch/riscv/Kconfig b/xen/arch/riscv/Kconfig
index 89876b32175d..12b337365f1f 100644
--- a/xen/arch/riscv/Kconfig
+++ b/xen/arch/riscv/Kconfig
@@ -1,5 +1,6 @@
 config RISCV
        def_bool y
+       select DOMAIN_BUILD_HELPERS
        select FUNCTION_ALIGNMENT_16B
        select GENERIC_BUG_FRAME
        select GENERIC_UART_INIT
diff --git a/xen/arch/riscv/include/asm/p2m.h b/xen/arch/riscv/include/asm/p2m.h
index c68494593fd9..083549ef9640 100644
--- a/xen/arch/riscv/include/asm/p2m.h
+++ b/xen/arch/riscv/include/asm/p2m.h
@@ -44,6 +44,9 @@
 #define P2M_LEVEL_MASK(p2m, lvl) \
     (P2M_TABLE_OFFSET(p2m, lvl) << P2M_GFN_LEVEL_SHIFT(lvl))
 
+/* Holds the bit size of IPAs in p2m tables */
+extern unsigned int p2m_ipa_bits;
+
 #define paddr_bits PADDR_BITS
 
 /* Get host p2m table */
diff --git a/xen/arch/riscv/p2m.c b/xen/arch/riscv/p2m.c
index f5b03e1e3264..62bd8a2f602f 100644
--- a/xen/arch/riscv/p2m.c
+++ b/xen/arch/riscv/p2m.c
@@ -51,6 +51,12 @@ static struct gstage_mode_desc __ro_after_init 
max_gstage_mode = {
     .name = "Bare",
 };
 
+/*
+ * Set to the maximum configured support for IPA bits, so the number of IPA 
bits can be
+ * restricted by external entity (e.g. IOMMU).
+ */
+unsigned int __read_mostly p2m_ipa_bits = PADDR_BITS;
+
 static void p2m_free_page(struct p2m_domain *p2m, struct page_info *pg);
 
 static inline void p2m_free_metadata_page(struct p2m_domain *p2m,
diff --git a/xen/include/public/arch-riscv.h b/xen/include/public/arch-riscv.h
index 360d8e6871ba..91cee3096041 100644
--- a/xen/include/public/arch-riscv.h
+++ b/xen/include/public/arch-riscv.h
@@ -50,6 +50,14 @@ typedef uint64_t xen_ulong_t;
 
 #if defined(__XEN__) || defined(__XEN_TOOLS__)
 
+#define GUEST_RAM_BANKS   1
+
+#define GUEST_RAM0_BASE   xen_mk_ullong(0x80000000) /* 2GB of low RAM @ 2GB */
+#define GUEST_RAM0_SIZE   xen_mk_ullong(0x80000000)
+
+#define GUEST_RAM_BANK_BASES   { GUEST_RAM0_BASE }
+#define GUEST_RAM_BANK_SIZES   { GUEST_RAM0_SIZE }
+
 struct vcpu_guest_context {
 };
 typedef struct vcpu_guest_context vcpu_guest_context_t;
-- 
2.52.0