'etc/reserved-memory-end' will allow QEMU to tell BIOS where PCI
BARs mapping could safely start in high memory.
Allowing BIOS to start mapping 64-bit PCI BARs at address where it
wouldn't conflict with other mappings QEMU might place before it.
That permits QEMU to reserve extra address space before
64-bit PCI hole for memory hotplug.
Signed-off-by: Igor Mammedov <imamm...@redhat.com>
---
hw/i386/pc.c | 9 ++++++++-
hw/i386/pc_piix.c | 3 +++
hw/i386/pc_q35.c | 3 +++
include/hw/i386/pc.h | 1 +
4 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 6fe1803..b164e37 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1200,7 +1200,8 @@ FWCfgState *pc_memory_init(MemoryRegion *system_memory,
}
/* initialize hotplug memory address space */
- if (ram_size < machine->init_args.maxram_size) {
+ if (guest_info->has_reserved_memory &&
+ (ram_size < machine->init_args.maxram_size)) {
ram_addr_t hotplug_mem_size =
machine->init_args.maxram_size - ram_size;
@@ -1233,6 +1234,12 @@ FWCfgState *pc_memory_init(MemoryRegion *system_memory,
fw_cfg = bochs_bios_init();
rom_set_fw(fw_cfg);
+ if (guest_info->has_reserved_memory && pcms->hotplug_memory_base) {
+ uint64_t *val = g_malloc(sizeof(*val));
+ *val = cpu_to_le64(ROUND_UP(pcms->hotplug_memory_base, 0x1ULL << 30));
+ fw_cfg_add_file(fw_cfg, "etc/reserved-memory-end", val, sizeof(*val));
+ }
+
if (linux_boot) {
load_linux(fw_cfg, kernel_filename, initrd_filename, kernel_cmdline,
below_4g_mem_size);
}
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 62f750d..098fbfc 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -66,6 +66,7 @@ static bool smbios_type1_defaults = true;
* pages in the host.
*/
static bool gigabyte_align = true;
+static bool has_reserved_memory = true;
/* PC hardware initialisation */
static void pc_init1(QEMUMachineInitArgs *args,
@@ -142,6 +143,7 @@ static void pc_init1(QEMUMachineInitArgs *args,
guest_info->has_pci_info = has_pci_info;
guest_info->isapc_ram_fw = !pci_enabled;
+ guest_info->has_reserved_memory = has_reserved_memory;
if (smbios_type1_defaults) {
/* These values are guest ABI, do not change */
@@ -264,6 +266,7 @@ static void pc_init_pci(QEMUMachineInitArgs *args)
static void pc_compat_2_0(QEMUMachineInitArgs *args)
{
+ has_reserved_memory = false;
}
static void pc_compat_1_7(QEMUMachineInitArgs *args)
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index ee68de7..89fd4b4 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -56,6 +56,7 @@ static bool smbios_type1_defaults = true;
* pages in the host.
*/
static bool gigabyte_align = true;
+static bool has_reserved_memory = true;
/* PC hardware initialisation */
static void pc_q35_init(QEMUMachineInitArgs *args)
@@ -129,6 +130,7 @@ static void pc_q35_init(QEMUMachineInitArgs *args)
guest_info->has_pci_info = has_pci_info;
guest_info->isapc_ram_fw = false;
guest_info->has_acpi_build = has_acpi_build;
+ guest_info->has_reserved_memory = has_reserved_memory;
if (smbios_type1_defaults) {
/* These values are guest ABI, do not change */
@@ -242,6 +244,7 @@ static void pc_q35_init(QEMUMachineInitArgs *args)
static void pc_compat_2_0(QEMUMachineInitArgs *args)
{
+ has_reserved_memory = false;
}
static void pc_compat_1_7(QEMUMachineInitArgs *args)
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index a1f21ba..36f2f52 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -77,6 +77,7 @@ struct PcGuestInfo {
uint64_t *node_cpu;
FWCfgState *fw_cfg;
bool has_acpi_build;
+ bool has_reserved_memory;
};
/* parallel.c */
--
1.9.0
