|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v5 6/7] xen/riscv: page table handling
Implement map_pages_to_xen() which requires several
functions to manage page tables and entries:
- pt_update()
- pt_mapping_level()
- pt_update_entry()
- pt_next_level()
- pt_check_entry()
To support these operations, add functions for creating,
mapping, and unmapping Xen tables:
- create_table()
- map_table()
- unmap_table()
Introduce internal macros starting with PTE_* for convenience.
These macros closely resemble PTE bits, with the exception of
PTE_SMALL, which indicates that 4KB is needed.
In addition introduce flush_tlb_range_va() for TLB flushing across
CPUs after updating the PTE for the requested mapping.
Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
---
Changes in V5:
- s/xen_{un}map/{un}map
- introduce PTE_SMALL instead of PTE_BLOCK.
- update the comment above defintion of PTE_4K_PAGES.
- code style fixes.
- s/RV_STAGE1_MODE > SATP_MODE_SV48/RV_STAGE1_MODE > SATP_MODE_SV39 around
DECLARE_OFFSETS macros.
- change type of root_maddr from unsgined long to maddr_t.
- drop duplicated check ( if (rc) break ) in pt_update() inside while cycle.
- s/1U/1UL
- put 'spin_unlock(&xen_pt_lock);' ahead of TLB flush in pt_update().
- update the commit message.
- update the comment above ASSERT() in map_pages_to_xen() and also update
the check within ASSERT() to check that flags has PTE_VALID bit set.
- update the comment above pt_update() function.
- add the comment inside pt_check_entry().
- update the TLB flushing region in pt_update().
- s/alloc_only/alloc_tbl
---
Changes in V4:
- update the commit message.
- drop xen_ prefix for functions: xen_pt_update(), xen_pt_mapping_level(),
xen_pt_update_entry(), xen_pt_next_level(), xen_pt_check_entry().
- drop 'select GENERIC_PT' for CONFIG_RISCV. There is no GENERIC_PT anymore.
- update implementation of flush_xen_tlb_range_va and
s/flush_xen_tlb_range_va/flush_tlb_range_va
- s/pte_get_mfn/mfn_from_pte. Others similar definitions I decided not to
touch as
they were introduced before and this patter of naming such type of macros
will be applied
for newly introduced macros.
- drop _PAGE_* definitions and use analogues of PTE_*.
- introduce PTE_{W,X,R}_MASK and drop PAGE_{XN,W,X}_MASK. Also drop
_PAGE_{*}_BIT
- introduce PAGE_HYPERVISOR_RX.
- drop unused now l3_table_offset.
- drop struct pt_t as it was used only for one function. If it will be needed
in the future
pt_t will be re-introduced.
- code styles fixes in pte_is_table(). drop level argument from t.
- update implementation and prototype of pte_is_mapping().
- drop level argument from pt_next_level().
- introduce definition of SATP_PPN_MASK.
- isolate PPN of CSR_SATP before shift by PAGE_SHIFT.
- drop set_permission() functions as it is not used more then once.
- update prototype of pt_check_entry(): drop level argument as it is not used.
- pt_check_entry():
- code style fixes
- update the sanity check when modifying an entry
- update the sanity check when when removing a mapping.
- s/read_only/alloc_only.
- code style fixes for pt_next_level().
- pt_update_entry() changes:
- drop arch_level variable inisde pt_update_entry()
- drop convertion near virt to paddr_t in DECLARE_OFFSETS(offsets, virt);
- pull out "goto out inside first 'for' cycle.
- drop braces for 'if' cases which has only one line.
- ident 'out' label with one blank.
- update the comment above alloc_only and also definition to take into
account that if pte population was requested or not.
- drop target variable and rename arch_target argument of the function to
target.
- pt_mapping_level() changes:
- move the check if PTE_BLOCK should be mapped on the top of the function.
- change int i to unsigned int and update 'for' cycle correspondingly.
- update prototye of pt_update():
- drop the comment above nr_mfns and drop const to be consistent with other
arguments.
- always flush TLB at the end of the function as non-present entries can be
put
in the TLB.
- add fence before TLB flush to ensure that PTEs are all updated before
flushing.
- s/XEN_TABLE_NORMAL_PAGE/XEN_TABLE_NORMAL
- add a check in map_pages_to_xen() the mfn is not INVALID_MFN.
- add the comment on top of pt_update() how mfn = INVALID_MFN is considered.
- s/_PAGE_BLOCK/PTE_BLOCK.
- add the comment with additional explanation for PTE_BLOCK.
- drop defintion of FIRST_SIZE as it isn't used.
---
Changes in V3:
- new patch. ( Technically it is reworked version of the generic approach
which I tried to suggest in the previous version )
---
xen/arch/riscv/Makefile | 1 +
xen/arch/riscv/include/asm/flushtlb.h | 12 +
xen/arch/riscv/include/asm/mm.h | 2 +
xen/arch/riscv/include/asm/page.h | 57 +++
xen/arch/riscv/include/asm/riscv_encoding.h | 1 +
xen/arch/riscv/mm.c | 9 -
xen/arch/riscv/pt.c | 420 ++++++++++++++++++++
7 files changed, 493 insertions(+), 9 deletions(-)
create mode 100644 xen/arch/riscv/pt.c
diff --git a/xen/arch/riscv/Makefile b/xen/arch/riscv/Makefile
index 334fd24547..d058ea4e95 100644
--- a/xen/arch/riscv/Makefile
+++ b/xen/arch/riscv/Makefile
@@ -1,6 +1,7 @@
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
obj-y += entry.o
obj-y += mm.o
+obj-y += pt.o
obj-$(CONFIG_RISCV_64) += riscv64/
obj-y += sbi.o
obj-y += setup.o
diff --git a/xen/arch/riscv/include/asm/flushtlb.h
b/xen/arch/riscv/include/asm/flushtlb.h
index f4a735fd6c..031d781aa2 100644
--- a/xen/arch/riscv/include/asm/flushtlb.h
+++ b/xen/arch/riscv/include/asm/flushtlb.h
@@ -5,12 +5,24 @@
#include <xen/bug.h>
#include <xen/cpumask.h>
+#include <asm/sbi.h>
+
/* Flush TLB of local processor for address va. */
static inline void flush_tlb_one_local(vaddr_t va)
{
asm volatile ( "sfence.vma %0" :: "r" (va) : "memory" );
}
+/*
+ * Flush a range of VA's hypervisor mappings from the TLB of all
+ * processors in the inner-shareable domain.
+ */
+static inline void flush_tlb_range_va(vaddr_t va, size_t size)
+{
+ BUG_ON(!sbi_has_rfence());
+ sbi_remote_sfence_vma(NULL, va, size);
+}
+
/*
* Filter the given set of CPUs, removing those that definitely flushed their
* TLB since @page_timestamp.
diff --git a/xen/arch/riscv/include/asm/mm.h b/xen/arch/riscv/include/asm/mm.h
index a0bdc2bc3a..ce1557bb27 100644
--- a/xen/arch/riscv/include/asm/mm.h
+++ b/xen/arch/riscv/include/asm/mm.h
@@ -42,6 +42,8 @@ static inline void *maddr_to_virt(paddr_t ma)
#define virt_to_mfn(va) __virt_to_mfn(va)
#define mfn_to_virt(mfn) __mfn_to_virt(mfn)
+#define mfn_from_pte(pte) maddr_to_mfn(pte_to_paddr(pte))
+
struct page_info
{
/* Each frame can be threaded onto a doubly-linked list. */
diff --git a/xen/arch/riscv/include/asm/page.h
b/xen/arch/riscv/include/asm/page.h
index 55916eaa92..f148d82261 100644
--- a/xen/arch/riscv/include/asm/page.h
+++ b/xen/arch/riscv/include/asm/page.h
@@ -21,6 +21,11 @@
#define XEN_PT_LEVEL_MAP_MASK(lvl) (~(XEN_PT_LEVEL_SIZE(lvl) - 1))
#define XEN_PT_LEVEL_MASK(lvl) (VPN_MASK << XEN_PT_LEVEL_SHIFT(lvl))
+/*
+ * PTE format:
+ * | XLEN-1 10 | 9 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
+ * PFN reserved for SW D A G U X W R V
+ */
#define PTE_VALID BIT(0, UL)
#define PTE_READABLE BIT(1, UL)
#define PTE_WRITABLE BIT(2, UL)
@@ -34,15 +39,53 @@
#define PTE_LEAF_DEFAULT (PTE_VALID | PTE_READABLE | PTE_WRITABLE)
#define PTE_TABLE (PTE_VALID)
+#define PAGE_HYPERVISOR_RO (PTE_VALID | PTE_READABLE)
#define PAGE_HYPERVISOR_RW (PTE_VALID | PTE_READABLE | PTE_WRITABLE)
+#define PAGE_HYPERVISOR_RX (PTE_VALID | PTE_READABLE | PTE_EXECUTABLE)
#define PAGE_HYPERVISOR PAGE_HYPERVISOR_RW
+/*
+ * The PTE format does not contain the following bits within itself;
+ * they are created artificially to inform the Xen page table
+ * handling algorithm. These bits should not be explicitly written
+ * to the PTE entry.
+ */
+#define PTE_SMALL BIT(10, UL)
+#define PTE_POPULATE BIT(11, UL)
+
+#define PTE_R_MASK(x) ((x) & PTE_READABLE)
+#define PTE_W_MASK(x) ((x) & PTE_WRITABLE)
+#define PTE_X_MASK(x) ((x) & PTE_EXECUTABLE)
+
+#define PTE_RWX_MASK(x) ((x) & (PTE_READABLE | PTE_WRITABLE | PTE_EXECUTABLE))
+
/* Calculate the offsets into the pagetables for a given VA */
#define pt_linear_offset(lvl, va) ((va) >> XEN_PT_LEVEL_SHIFT(lvl))
#define pt_index(lvl, va) (pt_linear_offset((lvl), (va)) & VPN_MASK)
+#define PAGETABLE_ORDER_MASK ((_AC(1, U) << PAGETABLE_ORDER) - 1)
+#define TABLE_OFFSET(offs) (_AT(unsigned int, offs) & PAGETABLE_ORDER_MASK)
+
+#if RV_STAGE1_MODE > SATP_MODE_SV39
+#error "need to to update DECLARE_OFFSETS macros"
+#else
+
+#define l0_table_offset(va) TABLE_OFFSET(pt_linear_offset(0, va))
+#define l1_table_offset(va) TABLE_OFFSET(pt_linear_offset(1, va))
+#define l2_table_offset(va) TABLE_OFFSET(pt_linear_offset(2, va))
+
+/* Generate an array @var containing the offset for each level from @addr */
+#define DECLARE_OFFSETS(var, addr) \
+ const unsigned int var[] = { \
+ l0_table_offset(addr), \
+ l1_table_offset(addr), \
+ l2_table_offset(addr), \
+ }
+
+#endif
+
/* Page Table entry */
typedef struct {
#ifdef CONFIG_RISCV_64
@@ -68,6 +111,20 @@ static inline bool pte_is_valid(pte_t p)
return p.pte & PTE_VALID;
}
+inline bool pte_is_table(const pte_t p)
+{
+ return ((p.pte & (PTE_VALID |
+ PTE_READABLE |
+ PTE_WRITABLE |
+ PTE_EXECUTABLE)) == PTE_VALID);
+}
+
+static inline bool pte_is_mapping(const pte_t p)
+{
+ return (p.pte & PTE_VALID) &&
+ (p.pte & (PTE_WRITABLE | PTE_EXECUTABLE));
+}
+
static inline void invalidate_icache(void)
{
BUG_ON("unimplemented");
diff --git a/xen/arch/riscv/include/asm/riscv_encoding.h
b/xen/arch/riscv/include/asm/riscv_encoding.h
index 58abe5eccc..d80cef0093 100644
--- a/xen/arch/riscv/include/asm/riscv_encoding.h
+++ b/xen/arch/riscv/include/asm/riscv_encoding.h
@@ -164,6 +164,7 @@
#define SSTATUS_SD SSTATUS64_SD
#define SATP_MODE SATP64_MODE
#define SATP_MODE_SHIFT SATP64_MODE_SHIFT
+#define SATP_PPN_MASK _UL(0x00000FFFFFFFFFFF)
#define HGATP_PPN HGATP64_PPN
#define HGATP_VMID_SHIFT HGATP64_VMID_SHIFT
diff --git a/xen/arch/riscv/mm.c b/xen/arch/riscv/mm.c
index b8ff91cf4e..e8430def14 100644
--- a/xen/arch/riscv/mm.c
+++ b/xen/arch/riscv/mm.c
@@ -369,12 +369,3 @@ int destroy_xen_mappings(unsigned long s, unsigned long e)
BUG_ON("unimplemented");
return -1;
}
-
-int map_pages_to_xen(unsigned long virt,
- mfn_t mfn,
- unsigned long nr_mfns,
- unsigned int flags)
-{
- BUG_ON("unimplemented");
- return -1;
-}
diff --git a/xen/arch/riscv/pt.c b/xen/arch/riscv/pt.c
new file mode 100644
index 0000000000..15eb02fe9e
--- /dev/null
+++ b/xen/arch/riscv/pt.c
@@ -0,0 +1,420 @@
+#include <xen/bug.h>
+#include <xen/domain_page.h>
+#include <xen/errno.h>
+#include <xen/mm.h>
+#include <xen/mm-frame.h>
+#include <xen/pmap.h>
+#include <xen/spinlock.h>
+
+#include <asm/flushtlb.h>
+#include <asm/page.h>
+
+static inline const mfn_t get_root_page(void)
+{
+ paddr_t root_maddr = (csr_read(CSR_SATP) & SATP_PPN_MASK) << PAGE_SHIFT;
+
+ return maddr_to_mfn(root_maddr);
+}
+
+/* Sanity check of the entry. */
+static bool pt_check_entry(pte_t entry, mfn_t mfn, unsigned int flags)
+{
+ /*
+ * See the comment about the possible combination of (mfn, flags) in
+ * the comment above pt_update().
+ */
+
+ /* Sanity check when modifying an entry. */
+ if ( (flags & PTE_VALID) && mfn_eq(mfn, INVALID_MFN) )
+ {
+ /* We don't allow modifying an invalid entry. */
+ if ( !pte_is_valid(entry) )
+ {
+ printk("Modifying invalid entry is not allowed.\n");
+ return false;
+ }
+
+ /* We don't allow modifying a table entry */
+ if ( pte_is_table(entry) )
+ {
+ printk("Modifying a table entry is not allowed.\n");
+ return false;
+ }
+ }
+ /* Sanity check when inserting a mapping */
+ else if ( flags & PTE_VALID )
+ {
+ /* We should be here with a valid MFN. */
+ ASSERT(!mfn_eq(mfn, INVALID_MFN));
+
+ /*
+ * We don't allow replacing any valid entry.
+ *
+ * Note that the function pt_update() relies on this
+ * assumption and will skip the TLB flush (when Svvptc
+ * extension will be ratified). The function will need
+ * to be updated if the check is relaxed.
+ */
+ if ( pte_is_valid(entry) )
+ {
+ if ( pte_is_mapping(entry) )
+ printk("Changing MFN for a valid entry is not allowed
(%#"PRI_mfn" -> %#"PRI_mfn").\n",
+ mfn_x(mfn_from_pte(entry)), mfn_x(mfn));
+ else
+ printk("Trying to replace a table with a mapping.\n");
+ return false;
+ }
+ }
+ /* Sanity check when removing a mapping. */
+ else if ( (flags & (PTE_VALID | PTE_POPULATE)) == 0 )
+ {
+ /* We should be here with an invalid MFN. */
+ ASSERT(mfn_eq(mfn, INVALID_MFN));
+
+ /* We don't allow removing a table */
+ if ( pte_is_table(entry) )
+ {
+ printk("Removing a table is not allowed.\n");
+ return false;
+ }
+ }
+ /* Sanity check when populating the page-table. No check so far. */
+ else
+ {
+ ASSERT(flags & PTE_POPULATE);
+ /* We should be here with an invalid MFN */
+ ASSERT(mfn_eq(mfn, INVALID_MFN));
+ }
+
+ return true;
+}
+
+static pte_t *map_table(mfn_t mfn)
+{
+ /*
+ * During early boot, map_domain_page() may be unusable. Use the
+ * PMAP to map temporarily a page-table.
+ */
+ if ( system_state == SYS_STATE_early_boot )
+ return pmap_map(mfn);
+
+ return map_domain_page(mfn);
+}
+
+static void unmap_table(const pte_t *table)
+{
+ /*
+ * During early boot, map_table() will not use map_domain_page()
+ * but the PMAP.
+ */
+ if ( system_state == SYS_STATE_early_boot )
+ pmap_unmap(table);
+ else
+ unmap_domain_page(table);
+}
+
+static int create_table(pte_t *entry)
+{
+ mfn_t mfn;
+ void *p;
+ pte_t pte;
+
+ if ( system_state != SYS_STATE_early_boot )
+ {
+ struct page_info *pg = alloc_domheap_page(NULL, 0);
+
+ if ( pg == NULL )
+ return -ENOMEM;
+
+ mfn = page_to_mfn(pg);
+ }
+ else
+ mfn = alloc_boot_pages(1, 1);
+
+ p = map_table(mfn);
+ clear_page(p);
+ unmap_table(p);
+
+ pte = pte_from_mfn(mfn, PTE_TABLE);
+ write_pte(entry, pte);
+
+ return 0;
+}
+
+#define XEN_TABLE_MAP_FAILED 0
+#define XEN_TABLE_SUPER_PAGE 1
+#define XEN_TABLE_NORMAL 2
+
+/*
+ * Take the currently mapped table, find the corresponding entry,
+ * and map the next table, if available.
+ *
+ * The alloc_tbl parameters indicates whether intermediate tables should
+ * be allocated when not present.
+ *
+ * Return values:
+ * XEN_TABLE_MAP_FAILED: Either alloc_only was set and the entry
+ * was empty, or allocating a new page failed.
+ * XEN_TABLE_NORMAL: next level or leaf mapped normally
+ * XEN_TABLE_SUPER_PAGE: The next entry points to a superpage.
+ */
+static int pt_next_level(bool alloc_tbl, pte_t **table, unsigned int offset)
+{
+ pte_t *entry;
+ int ret;
+ mfn_t mfn;
+
+ entry = *table + offset;
+
+ if ( !pte_is_valid(*entry) )
+ {
+ if ( alloc_tbl )
+ return XEN_TABLE_MAP_FAILED;
+
+ ret = create_table(entry);
+ if ( ret )
+ return XEN_TABLE_MAP_FAILED;
+ }
+
+ if ( pte_is_mapping(*entry) )
+ return XEN_TABLE_SUPER_PAGE;
+
+ mfn = mfn_from_pte(*entry);
+
+ unmap_table(*table);
+ *table = map_table(mfn);
+
+ return XEN_TABLE_NORMAL;
+}
+
+/* Update an entry at the level @target. */
+static int pt_update_entry(mfn_t root, unsigned long virt,
+ mfn_t mfn, unsigned int target,
+ unsigned int flags)
+{
+ int rc;
+ unsigned int level = HYP_PT_ROOT_LEVEL;
+ pte_t *table;
+ /*
+ * The intermediate page table shouldn't be allocated when MFN isn't
+ * valid and we are not populating page table.
+ * This means we either modify permissions or remove an entry, or
+ * inserting brand new entry.
+ *
+ * See the comment above pt_update() for an additional explanation about
+ * combinations of (mfn, flags).
+ */
+ bool alloc_tbl = mfn_eq(mfn, INVALID_MFN) && !(flags & PTE_POPULATE);
+ pte_t pte, *entry;
+
+ /* convenience aliases */
+ DECLARE_OFFSETS(offsets, virt);
+
+ table = map_table(root);
+ for ( ; level > target; level-- )
+ {
+ rc = pt_next_level(alloc_tbl, &table, offsets[level]);
+ if ( rc == XEN_TABLE_MAP_FAILED )
+ {
+ rc = 0;
+
+ /*
+ * We are here because pt_next_level has failed to map
+ * the intermediate page table (e.g the table does not exist
+ * and the pt is read-only). It is a valid case when
+ * removing a mapping as it may not exist in the page table.
+ * In this case, just ignore it.
+ */
+ if ( flags & PTE_VALID )
+ {
+ printk("%s: Unable to map level %u\n", __func__, level);
+ rc = -ENOENT;
+ }
+
+ goto out;
+ }
+ else if ( rc != XEN_TABLE_NORMAL )
+ break;
+ }
+
+ if ( level != target )
+ {
+ printk("%s: Shattering superpage is not supported\n", __func__);
+ rc = -EOPNOTSUPP;
+ goto out;
+ }
+
+ entry = table + offsets[level];
+
+ rc = -EINVAL;
+ if ( !pt_check_entry(*entry, mfn, flags) )
+ goto out;
+
+ /* We are removing the page */
+ if ( !(flags & PTE_VALID) )
+ memset(&pte, 0x00, sizeof(pte));
+ else
+ {
+ /* We are inserting a mapping => Create new pte. */
+ if ( !mfn_eq(mfn, INVALID_MFN) )
+ pte = pte_from_mfn(mfn, PTE_VALID);
+ else /* We are updating the permission => Copy the current pte. */
+ pte = *entry;
+
+ /* update permission according to the flags */
+ pte.pte |= PTE_RWX_MASK(flags) | PTE_ACCESSED | PTE_DIRTY;
+ }
+
+ write_pte(entry, pte);
+
+ rc = 0;
+
+ out:
+ unmap_table(table);
+
+ return rc;
+}
+
+/* Return the level where mapping should be done */
+static int pt_mapping_level(unsigned long vfn, mfn_t mfn, unsigned long nr,
+ unsigned int flags)
+{
+ unsigned int level = 0;
+ unsigned long mask;
+ unsigned int i;
+
+ /* Use blocking mapping unless the caller requests 4K mapping */
+ if ( unlikely(flags & PTE_SMALL) )
+ return level;
+
+ /*
+ * Don't take into account the MFN when removing mapping (i.e
+ * MFN_INVALID) to calculate the correct target order.
+ *
+ * `vfn` and `mfn` must be both superpage aligned.
+ * They are or-ed together and then checked against the size of
+ * each level.
+ *
+ * `left` is not included and checked separately to allow
+ * superpage mapping even if it is not properly aligned (the
+ * user may have asked to map 2MB + 4k).
+ */
+ mask = !mfn_eq(mfn, INVALID_MFN) ? mfn_x(mfn) : 0;
+ mask |= vfn;
+
+ for ( i = HYP_PT_ROOT_LEVEL; i != 0; i-- )
+ {
+ if ( !(mask & (BIT(XEN_PT_LEVEL_ORDER(i), UL) - 1)) &&
+ (nr >= BIT(XEN_PT_LEVEL_ORDER(i), UL)) )
+ {
+ level = i;
+ break;
+ }
+ }
+
+ return level;
+}
+
+static DEFINE_SPINLOCK(xen_pt_lock);
+
+/*
+ * If `mfn` equals `INVALID_MFN`, it indicates that the following page table
+ * update operation might be related to either populating the table (
+ * PTE_POPULATE will be set additionaly), destroying a mapping, or modifying
+ * an existing mapping.
+ *
+ * If `mfn` is valid and flags has PTE_VALID bit set then it means that
+ * inserting will be done.
+ */
+static int pt_update(unsigned long virt,
+ mfn_t mfn,
+ unsigned long nr_mfns,
+ unsigned int flags)
+{
+ int rc = 0;
+ unsigned long vfn = virt >> PAGE_SHIFT;
+ unsigned long left = nr_mfns;
+
+ const mfn_t root = get_root_page();
+
+ /*
+ * It is bad idea to have mapping both writeable and
+ * executable.
+ * When modifying/creating mapping (i.e PTE_VALID is set),
+ * prevent any update if this happen.
+ */
+ if ( (flags & PTE_VALID) && PTE_W_MASK(flags) && PTE_X_MASK(flags) )
+ {
+ printk("Mappings should not be both Writeable and Executable.\n");
+ return -EINVAL;
+ }
+
+ if ( !IS_ALIGNED(virt, PAGE_SIZE) )
+ {
+ printk("The virtual address is not aligned to the page-size.\n");
+ return -EINVAL;
+ }
+
+ spin_lock(&xen_pt_lock);
+
+ while ( left )
+ {
+ unsigned int order, level;
+
+ level = pt_mapping_level(vfn, mfn, left, flags);
+ order = XEN_PT_LEVEL_ORDER(level);
+
+ ASSERT(left >= BIT(order, UL));
+
+ rc = pt_update_entry(root, vfn << PAGE_SHIFT, mfn, level, flags);
+ if ( rc )
+ break;
+
+ vfn += 1UL << order;
+ if ( !mfn_eq(mfn, INVALID_MFN) )
+ mfn = mfn_add(mfn, 1UL << order);
+
+ left -= (1UL << order);
+ }
+
+ /* Ensure that PTEs are all updated before flushing */
+ RISCV_FENCE(rw, rw);
+
+ spin_unlock(&xen_pt_lock);
+
+ /*
+ * Always flush TLB at the end of the function as non-present entries
+ * can be put in the TLB.
+ *
+ * The remote fence operation applies to the entire address space if
+ * either:
+ * - start and size are both 0, or
+ * - size is equal to 2^XLEN-1.
+ *
+ * TODO: come up with something which will allow not to flash the entire
+ * address space.
+ */
+ flush_tlb_range_va(0, 0);
+
+ return rc;
+}
+
+int map_pages_to_xen(unsigned long virt,
+ mfn_t mfn,
+ unsigned long nr_mfns,
+ unsigned int flags)
+{
+ /*
+ * Ensure that flags has PTE_VALID bit as map_pages_to_xen() is supposed
+ * to create a mapping.
+ *
+ * Ensure that we have a valid MFN before proceeding.
+ *
+ * If the MFN is invalid, pt_update() might misinterpret the operation,
+ * treating it as either a population, a mapping destruction,
+ * or a mapping modification.
+ */
+ ASSERT(!mfn_eq(mfn, INVALID_MFN) || (flags & PTE_VALID));
+
+ return pt_update(virt, mfn, nr_mfns, flags);
+}
--
2.46.0
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |