target/i386: Add Intel HAX files

That's a forward port of the core HAX interface code from the
emu-2.2-release branch in the external/qemu-android repository as used by
the Android emulator.

The original commit was "target/i386: Add Intel HAX to android emulator"
saying:
"""
  Backport of 2b3098ff27bab079caab9b46b58546b5036f5c0c
  from studio-1.4-dev into emu-master-dev

    Intel HAX (harware acceleration) will enhance android emulator performance
    in Windows and Mac OS X in the systems powered by Intel processors with
    "Intel Hardware Accelerated Execution Manager" package installed when
    user runs android emulator with Intel target.

    Signed-off-by: David Chou <david.j.chou@intel.com>
"""

It has been modified to build and run along with the current code base.
The formatting has been fixed to go through scripts/checkpatch.pl,
and the DPRINTF macros have been updated to get the instanciations checked by
the compiler.

The FPU registers saving/restoring has been updated to match the current
QEMU registers layout.

The implementation has been simplified by doing the following modifications:
- removing the code for supporting the hardware without Unrestricted Guest (UG)
  mode (including all the code to fallback on TCG emulation).
- not including the Darwin support (which is not yet debugged/tested).
- simplifying the initialization by removing the leftovers from the Android
  specific code, then trimming down the remaining logic.
- removing the unused MemoryListener callbacks.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Message-Id: <e1023837f8d0e4c470f6c4a3bf643971b2bca5be.1484045952.git.vpalatin@chromium.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 289 insertions, 0 deletions

diff --git a/target/i386/hax-mem.c b/target/i386/hax-mem.c
new file mode 100644
index 0000000000..2884040021
--- /dev/null
+++ b/target/i386/hax-mem.c
@@ -0,0 +1,289 @@
+/*
+ * HAX memory mapping operations
+ *
+ * Copyright (c) 2015-16 Intel Corporation
+ * Copyright 2016 Google, Inc.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "exec/address-spaces.h"
+#include "exec/exec-all.h"
+
+#include "target/i386/hax-i386.h"
+#include "qemu/queue.h"
+
+#define DEBUG_HAX_MEM 0
+
+#define DPRINTF(fmt, ...) \
+    do { \
+        if (DEBUG_HAX_MEM) { \
+            fprintf(stdout, fmt, ## __VA_ARGS__); \
+        } \
+    } while (0)
+
+/**
+ * HAXMapping: describes a pending guest physical memory mapping
+ *
+ * @start_pa: a guest physical address marking the start of the region; must be
+ *            page-aligned
+ * @size: a guest physical address marking the end of the region; must be
+ *          page-aligned
+ * @host_va: the host virtual address of the start of the mapping
+ * @flags: mapping parameters e.g. HAX_RAM_INFO_ROM or HAX_RAM_INFO_INVALID
+ * @entry: additional fields for linking #HAXMapping instances together
+ */
+typedef struct HAXMapping {
+    uint64_t start_pa;
+    uint32_t size;
+    uint64_t host_va;
+    int flags;
+    QTAILQ_ENTRY(HAXMapping) entry;
+} HAXMapping;
+
+/*
+ * A doubly-linked list (actually a tail queue) of the pending page mappings
+ * for the ongoing memory transaction.
+ *
+ * It is used to optimize the number of page mapping updates done through the
+ * kernel module. For example, it's effective when a driver is digging an MMIO
+ * hole inside an existing memory mapping. It will get a deletion of the whole
+ * region, then the addition of the 2 remaining RAM areas around the hole and
+ * finally the memory transaction commit. During the commit, it will effectively
+ * send to the kernel only the removal of the pages from the MMIO hole after
+ * having computed locally the result of the deletion and additions.
+ */
+static QTAILQ_HEAD(HAXMappingListHead, HAXMapping) mappings =
+    QTAILQ_HEAD_INITIALIZER(mappings);
+
+/**
+ * hax_mapping_dump_list: dumps @mappings to stdout (for debugging)
+ */
+static void hax_mapping_dump_list(void)
+{
+    HAXMapping *entry;
+
+    DPRINTF("%s updates:\n", __func__);
+    QTAILQ_FOREACH(entry, &mappings, entry) {
+        DPRINTF("\t%c 0x%016" PRIx64 "->0x%016" PRIx64 " VA 0x%016" PRIx64
+                "%s\n", entry->flags & HAX_RAM_INFO_INVALID ? '-' : '+',
+                entry->start_pa, entry->start_pa + entry->size, entry->host_va,
+                entry->flags & HAX_RAM_INFO_ROM ? " ROM" : "");
+    }
+}
+
+static void hax_insert_mapping_before(HAXMapping *next, uint64_t start_pa,
+                                      uint32_t size, uint64_t host_va,
+                                      uint8_t flags)
+{
+    HAXMapping *entry;
+
+    entry = g_malloc0(sizeof(*entry));
+    entry->start_pa = start_pa;
+    entry->size = size;
+    entry->host_va = host_va;
+    entry->flags = flags;
+    if (!next) {
+        QTAILQ_INSERT_TAIL(&mappings, entry, entry);
+    } else {
+        QTAILQ_INSERT_BEFORE(next, entry, entry);
+    }
+}
+
+static bool hax_mapping_is_opposite(HAXMapping *entry, uint64_t host_va,
+                                    uint8_t flags)
+{
+    /* removed then added without change for the read-only flag */
+    bool nop_flags = (entry->flags ^ flags) == HAX_RAM_INFO_INVALID;
+
+    return (entry->host_va == host_va) && nop_flags;
+}
+
+static void hax_update_mapping(uint64_t start_pa, uint32_t size,
+                               uint64_t host_va, uint8_t flags)
+{
+    uint64_t end_pa = start_pa + size;
+    uint32_t chunk_sz;
+    HAXMapping *entry, *next;
+
+    QTAILQ_FOREACH_SAFE(entry, &mappings, entry, next) {
+        if (start_pa >= entry->start_pa + entry->size) {
+            continue;
+        }
+        if (start_pa < entry->start_pa) {
+            chunk_sz = end_pa <= entry->start_pa ? size
+                                                 : entry->start_pa - start_pa;
+            hax_insert_mapping_before(entry, start_pa, chunk_sz,
+                                      host_va, flags);
+            start_pa += chunk_sz;
+            host_va += chunk_sz;
+            size -= chunk_sz;
+        }
+        chunk_sz = MIN(size, entry->size);
+        if (chunk_sz) {
+            bool nop = hax_mapping_is_opposite(entry, host_va, flags);
+            bool partial = chunk_sz < entry->size;
+            if (partial) {
+                /* remove the beginning of the existing chunk */
+                entry->start_pa += chunk_sz;
+                entry->host_va += chunk_sz;
+                entry->size -= chunk_sz;
+                if (!nop) {
+                    hax_insert_mapping_before(entry, start_pa, chunk_sz,
+                                              host_va, flags);
+                }
+            } else { /* affects the full mapping entry */
+                if (nop) { /* no change to this mapping, remove it */
+                    QTAILQ_REMOVE(&mappings, entry, entry);
+                    g_free(entry);
+                } else { /* update mapping properties */
+                    entry->host_va = host_va;
+                    entry->flags = flags;
+                }
+            }
+            start_pa += chunk_sz;
+            host_va += chunk_sz;
+            size -= chunk_sz;
+        }
+        if (!size) { /* we are done */
+            break;
+        }
+    }
+    if (size) { /* add the leftover */
+        hax_insert_mapping_before(NULL, start_pa, size, host_va, flags);
+    }
+}
+
+static void hax_process_section(MemoryRegionSection *section, uint8_t flags)
+{
+    MemoryRegion *mr = section->mr;
+    hwaddr start_pa = section->offset_within_address_space;
+    ram_addr_t size = int128_get64(section->size);
+    unsigned int delta;
+    uint64_t host_va;
+
+    /* We only care about RAM pages */
+    if (!memory_region_is_ram(mr)) {
+        return;
+    }
+
+    /* Adjust start_pa and size so that they are page-aligned. (Cf
+     * kvm_set_phys_mem() in kvm-all.c).
+     */
+    delta = qemu_real_host_page_size - (start_pa & ~qemu_real_host_page_mask);
+    delta &= ~qemu_real_host_page_mask;
+    if (delta > size) {
+        return;
+    }
+    start_pa += delta;
+    size -= delta;
+    size &= qemu_real_host_page_mask;
+    if (!size || (start_pa & ~qemu_real_host_page_mask)) {
+        return;
+    }
+
+    host_va = (uintptr_t)memory_region_get_ram_ptr(mr)
+            + section->offset_within_region + delta;
+    if (memory_region_is_rom(section->mr)) {
+        flags |= HAX_RAM_INFO_ROM;
+    }
+
+    /* the kernel module interface uses 32-bit sizes (but we could split...) */
+    g_assert(size <= UINT32_MAX);
+
+    hax_update_mapping(start_pa, size, host_va, flags);
+}
+
+static void hax_region_add(MemoryListener *listener,
+                           MemoryRegionSection *section)
+{
+    memory_region_ref(section->mr);
+    hax_process_section(section, 0);
+}
+
+static void hax_region_del(MemoryListener *listener,
+                           MemoryRegionSection *section)
+{
+    hax_process_section(section, HAX_RAM_INFO_INVALID);
+    memory_region_unref(section->mr);
+}
+
+static void hax_transaction_begin(MemoryListener *listener)
+{
+    g_assert(QTAILQ_EMPTY(&mappings));
+}
+
+static void hax_transaction_commit(MemoryListener *listener)
+{
+    if (!QTAILQ_EMPTY(&mappings)) {
+        HAXMapping *entry, *next;
+
+        if (DEBUG_HAX_MEM) {
+            hax_mapping_dump_list();
+        }
+        QTAILQ_FOREACH_SAFE(entry, &mappings, entry, next) {
+            if (entry->flags & HAX_RAM_INFO_INVALID) {
+                /* for unmapping, put the values expected by the kernel */
+                entry->flags = HAX_RAM_INFO_INVALID;
+                entry->host_va = 0;
+            }
+            if (hax_set_ram(entry->start_pa, entry->size,
+                            entry->host_va, entry->flags)) {
+                fprintf(stderr, "%s: Failed mapping @0x%016" PRIx64 "+0x%"
+                        PRIx32 " flags %02x\n", __func__, entry->start_pa,
+                        entry->size, entry->flags);
+            }
+            QTAILQ_REMOVE(&mappings, entry, entry);
+            g_free(entry);
+        }
+    }
+}
+
+/* currently we fake the dirty bitmap sync, always dirty */
+static void hax_log_sync(MemoryListener *listener,
+                         MemoryRegionSection *section)
+{
+    MemoryRegion *mr = section->mr;
+
+    if (!memory_region_is_ram(mr)) {
+        /* Skip MMIO regions */
+        return;
+    }
+
+    memory_region_set_dirty(mr, 0, int128_get64(section->size));
+}
+
+static MemoryListener hax_memory_listener = {
+    .begin = hax_transaction_begin,
+    .commit = hax_transaction_commit,
+    .region_add = hax_region_add,
+    .region_del = hax_region_del,
+    .log_sync = hax_log_sync,
+    .priority = 10,
+};
+
+static void hax_ram_block_added(RAMBlockNotifier *n, void *host, size_t size)
+{
+    /*
+     * In HAX, QEMU allocates the virtual address, and HAX kernel
+     * populates the memory with physical memory. Currently we have no
+     * paging, so user should make sure enough free memory in advance.
+     */
+    if (hax_populate_ram((uint64_t)(uintptr_t)host, size) < 0) {
+        fprintf(stderr, "HAX failed to populate RAM");
+        abort();
+    }
+}
+
+static struct RAMBlockNotifier hax_ram_notifier = {
+    .ram_block_added = hax_ram_block_added,
+};
+
+void hax_memory_init(void)
+{
+    ram_block_notifier_add(&hax_ram_notifier);
+    memory_listener_register(&hax_memory_listener, &address_space_memory);
+}