i386: move hax accel files into hax/

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20201212155530.23098-4-cfontana@suse.de>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

1 files changed, 321 insertions, 0 deletions

diff --git a/target/i386/hax/hax-mem.c b/target/i386/hax/hax-mem.c
new file mode 100644
index 0000000000..71e637cf16
--- /dev/null
+++ b/target/i386/hax/hax-mem.c
@@ -0,0 +1,321 @@
+/*
+ * 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 "qemu/error-report.h"
+
+#include "hax-cpus.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(, 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;
+    HAXMapping *entry, *next;
+
+    QTAILQ_FOREACH_SAFE(entry, &mappings, entry, next) {
+        uint32_t chunk_sz;
+        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;
+        } else if (start_pa > entry->start_pa) {
+            /* split the existing chunk at start_pa */
+            chunk_sz = start_pa - entry->start_pa;
+            hax_insert_mapping_before(entry, entry->start_pa, chunk_sz,
+                                      entry->host_va, entry->flags);
+            entry->start_pa += chunk_sz;
+            entry->host_va += chunk_sz;
+            entry->size -= chunk_sz;
+        }
+        /* now start_pa == entry->start_pa */
+        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;
+    uint32_t max_mapping_size;
+
+    /* We only care about RAM and ROM regions */
+    if (!memory_region_is_ram(mr)) {
+        if (memory_region_is_romd(mr)) {
+            /* HAXM kernel module does not support ROMD yet  */
+            warn_report("Ignoring ROMD region 0x%016" PRIx64 "->0x%016" PRIx64,
+                        start_pa, start_pa + size);
+        }
+        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:
+     * https://github.com/intel/haxm/blob/master/API.md#hax_vm_ioctl_set_ram
+     *
+     * If the mapping size is longer than 32 bits, we can't process it in one
+     * call into the kernel. Instead, we split the mapping into smaller ones,
+     * and call hax_update_mapping() on each.
+     */
+    max_mapping_size = UINT32_MAX & qemu_real_host_page_mask;
+    while (size > max_mapping_size) {
+        hax_update_mapping(start_pa, max_mapping_size, host_va, flags);
+        start_pa += max_mapping_size;
+        size -= max_mapping_size;
+        host_va += max_mapping_size;
+    }
+    /* Now size <= max_mapping_size */
+    hax_update_mapping(start_pa, (uint32_t)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)
+{
+    /*
+     * We must register each RAM block with the HAXM kernel module, or
+     * hax_set_ram() will fail for any mapping into the RAM block:
+     * https://github.com/intel/haxm/blob/master/API.md#hax_vm_ioctl_alloc_ram
+     *
+     * Old versions of the HAXM kernel module (< 6.2.0) used to preallocate all
+     * host physical pages for the RAM block as part of this registration
+     * process, hence the name hax_populate_ram().
+     */
+    if (hax_populate_ram((uint64_t)(uintptr_t)host, size) < 0) {
+        fprintf(stderr, "HAX failed to populate RAM\n");
+        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);
+}