From d70414a5788c3d51f8ce4d2f437e669e6b99dc59 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Mon, 9 Feb 2015 13:59:53 +0000 Subject: [PATCH] acpi: update RSDP on guest access RSDT offset can change across reboots and that makes immutable RSDP, which is build at startup, point to incorrect place in ACPI table blob. That results in BIOS corrupting tables and guest OS failing to find ACPI tables. We really should have put it in a ROM region, but we can't change that for old machine types, let's just set the callback and update it explicitly. Signed-off-by: Michael S. Tsirkin Signed-off-by: Igor Mammedov Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Reviewed-by: Marcel Apfelbaum --- hw/i386/acpi-build.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index 5737ed061c..d9b99bcf13 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -1367,6 +1367,7 @@ struct AcpiBuildState { /* Is table patched? */ uint8_t patched; PcGuestInfo *guest_info; + void *rsdp; } AcpiBuildState; static bool acpi_get_mcfg(AcpiMcfgInfo *mcfg) @@ -1501,8 +1502,6 @@ void acpi_build(PcGuestInfo *guest_info, AcpiBuildTables *tables) /* We'll expose it all to Guest so we want to reduce * chance of size changes. - * RSDP is small so it's easy to keep it immutable, no need to - * bother with alignment. * * We used to align the tables to 4k, but of course this would * too simple to be enough. 4k turned out to be too small an @@ -1574,6 +1573,7 @@ static void acpi_build_update(void *build_opaque, uint32_t offset) memcpy(qemu_get_ram_ptr(build_state->table_ram), tables.table_data->data, build_state->table_size); + memcpy(build_state->rsdp, tables.rsdp->data, acpi_data_len(tables.rsdp)); cpu_physical_memory_set_dirty_range_nocode(build_state->table_ram, build_state->table_size); @@ -1646,11 +1646,14 @@ void acpi_setup(PcGuestInfo *guest_info) tables.tcpalog->data, acpi_data_len(tables.tcpalog)); /* - * RSDP is small so it's easy to keep it immutable, no need to - * bother with ROM blobs. + * Though RSDP is small, its contents isn't immutable, so + * update it along with the rest of tables on guest access. */ - fw_cfg_add_file(guest_info->fw_cfg, ACPI_BUILD_RSDP_FILE, - tables.rsdp->data, acpi_data_len(tables.rsdp)); + fw_cfg_add_file_callback(guest_info->fw_cfg, ACPI_BUILD_RSDP_FILE, + acpi_build_update, build_state, + tables.rsdp->data, acpi_data_len(tables.rsdp)); + + build_state->rsdp = tables.rsdp->data; qemu_register_reset(acpi_build_reset, build_state); acpi_build_reset(build_state);