'etc/pcimem64-minimum-address' will allow QEMU to tell BIOS where PCI memory address space mapping could 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. Related SeaBIOS patch: http://patchwork.ozlabs.org/patch/283623/ Signed-off-by: Igor Mammedov <imamm...@redhat.com> --- hw/i386/pc.c | 14 +++++++++++++- hw/pci-host/piix.c | 3 ++- hw/pci-host/q35.c | 3 ++- include/hw/i386/pc.h | 3 ++- 4 files changed, 19 insertions(+), 4 deletions(-) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index 340c696..53d07a4 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -1055,11 +1055,23 @@ PcGuestInfo *pc_guest_info_init(ram_addr_t below_4g_mem_size, /* setup pci memory address space mapping into system address space */ void pc_pci_as_mapping_init(Object *owner, MemoryRegion *system_memory, - MemoryRegion *pci_address_space) + MemoryRegion *pci_address_space, + uint64_t pcimem64_min_addr) { + uint64_t *val; + FWCfgState *fw_cfg = fw_cfg_find(); + /* Set to lower priority than RAM */ memory_region_add_subregion_overlap(system_memory, 0x0, pci_address_space, -1); + g_assert(fw_cfg); + /* + * Align address at 1G, this makes sure it can be exactly covered + * with a PAT entry even when using huge pages. + */ + val = g_malloc(sizeof(*val)); + *val = cpu_to_le64(ROUND_UP(pcimem64_min_addr, 0x1ULL << 30)); + fw_cfg_add_file(fw_cfg, "etc/pcimem64-minimum-address", val, sizeof(*val)); } void pc_acpi_init(const char *default_dsdt) diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c index d34d20b..fcebe9a 100644 --- a/hw/pci-host/piix.c +++ b/hw/pci-host/piix.c @@ -351,7 +351,8 @@ PCIBus *i440fx_init(PCII440FXState **pi440fx_state, /* setup pci memory mapping */ pc_pci_as_mapping_init(OBJECT(f), f->system_memory, - f->pci_address_space); + f->pci_address_space, + 0x100000000ULL + above_4g_mem_size); memory_region_init_alias(&f->smram_region, OBJECT(d), "smram-region", f->pci_address_space, 0xa0000, 0x20000); diff --git a/hw/pci-host/q35.c b/hw/pci-host/q35.c index 3e82caf..0f3aabc 100644 --- a/hw/pci-host/q35.c +++ b/hw/pci-host/q35.c @@ -339,7 +339,8 @@ static int mch_init(PCIDevice *d) /* setup pci memory mapping */ pc_pci_as_mapping_init(OBJECT(mch), mch->system_memory, - mch->pci_address_space); + mch->pci_address_space, + 0x100000000ULL + mch->above_4g_mem_size); /* smram */ cpu_smm_register(&mch_set_smm, mch); diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h index de5a347..9b9bcf0 100644 --- a/include/hw/i386/pc.h +++ b/include/hw/i386/pc.h @@ -110,7 +110,8 @@ PcGuestInfo *pc_guest_info_init(ram_addr_t below_4g_mem_size, void pc_pci_as_mapping_init(Object *owner, MemoryRegion *system_memory, - MemoryRegion *pci_address_space); + MemoryRegion *pci_address_space, + uint64_t pcimem64_min_addr); FWCfgState *pc_memory_init(MemoryRegion *system_memory, const char *kernel_filename, -- 1.7.1
