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[Qemu-ppc] [PULL 17/19] spapr_pci: Advertise BAR reallocation capability
From: |
David Gibson |
Subject: |
[Qemu-ppc] [PULL 17/19] spapr_pci: Advertise BAR reallocation capability |
Date: |
Thu, 29 Aug 2019 16:08:25 +1000 |
From: Alexey Kardashevskiy <address@hidden>
The pseries guests do not normally allocate PCI resources and rely on
the system firmware doing so. Furthermore at least at some point in
the past the pseries guests won't even allowed to change BARs, probably
it is still the case for phyp. So since the initial commit we have [1]
which prevents resource reallocation.
This is not a problem until we want specific BAR alignments, for example,
PAGE_SIZE==64k to make sure we can still map MMIO BARs directly. For
the boot time devices we handle this in SLOF [2] but since QEMU's RTAS
does not allocate BARs, the guest does this instead and does not align
BARs even if Linux is given pci=resource_alignment=16@pci:0:0 as
PCI_PROBE_ONLY makes Linux ignore alignment requests.
ARM folks added a dial to control PCI_PROBE_ONLY via the device tree [3].
This makes use of the dial to advertise to the guest that we can handle
BAR reassignments. This limits the change to the latest pseries machine
to avoid old guests explosion.
We do not remove the flag from [1] as pseries guests are still supported
under phyp so having that removed may cause problems.
[1]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/platforms/pseries/setup.c?h=v5.1#n773
[2]
https://git.qemu.org/?p=SLOF.git;a=blob;f=board-qemu/slof/pci-phb.fs;h=06729bcf77a0d4e900c527adcd9befe2a269f65d;hb=HEAD#l338
[3]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f81c11af
Signed-off-by: Alexey Kardashevskiy <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Greg Kurz <address@hidden>
Signed-off-by: David Gibson <address@hidden>
---
hw/ppc/spapr.c | 9 +++++++++
include/hw/ppc/spapr.h | 1 +
2 files changed, 10 insertions(+)
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index d063312a3b..447fb5c4ea 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1168,6 +1168,7 @@ static void
spapr_dt_ov5_platform_support(SpaprMachineState *spapr, void *fdt,
static void spapr_dt_chosen(SpaprMachineState *spapr, void *fdt)
{
MachineState *machine = MACHINE(spapr);
+ SpaprMachineClass *smc = SPAPR_MACHINE_GET_CLASS(machine);
int chosen;
const char *boot_device = machine->boot_order;
char *stdout_path = spapr_vio_stdout_path(spapr->vio_bus);
@@ -1225,6 +1226,11 @@ static void spapr_dt_chosen(SpaprMachineState *spapr,
void *fdt)
_FDT(fdt_setprop_string(fdt, chosen, "stdout-path", stdout_path));
}
+ /* We can deal with BAR reallocation just fine, advertise it to the guest
*/
+ if (smc->linux_pci_probe) {
+ _FDT(fdt_setprop_cell(fdt, chosen, "linux,pci-probe-only", 0));
+ }
+
spapr_dt_ov5_platform_support(spapr, fdt, chosen);
g_free(stdout_path);
@@ -4476,6 +4482,7 @@ static void spapr_machine_class_init(ObjectClass *oc,
void *data)
spapr_caps_add_properties(smc, &error_abort);
smc->irq = &spapr_irq_dual;
smc->dr_phb_enabled = true;
+ smc->linux_pci_probe = true;
}
static const TypeInfo spapr_machine_info = {
@@ -4535,12 +4542,14 @@ DEFINE_SPAPR_MACHINE(4_2, "4.2", true);
*/
static void spapr_machine_4_1_class_options(MachineClass *mc)
{
+ SpaprMachineClass *smc = SPAPR_MACHINE_CLASS(mc);
static GlobalProperty compat[] = {
/* Only allow 4kiB and 64kiB IOMMU pagesizes */
{ TYPE_SPAPR_PCI_HOST_BRIDGE, "pgsz", "0x11000" },
};
spapr_machine_4_2_class_options(mc);
+ smc->linux_pci_probe = false;
compat_props_add(mc->compat_props, hw_compat_4_1, hw_compat_4_1_len);
compat_props_add(mc->compat_props, compat, G_N_ELEMENTS(compat));
}
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index fa7c380edb..03111fd55b 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -121,6 +121,7 @@ struct SpaprMachineClass {
bool legacy_irq_allocation;
bool broken_host_serial_model; /* present real host info to the guest */
bool pre_4_1_migration; /* don't migrate hpt-max-page-size */
+ bool linux_pci_probe;
void (*phb_placement)(SpaprMachineState *spapr, uint32_t index,
uint64_t *buid, hwaddr *pio,
--
2.21.0
- [Qemu-ppc] [PULL 11/19] target/ppc: Set float_tininess_before_rounding at cpu reset, (continued)
- [Qemu-ppc] [PULL 11/19] target/ppc: Set float_tininess_before_rounding at cpu reset, David Gibson, 2019/08/29
- [Qemu-ppc] [PULL 10/19] pseries: Fix compat_pvr on reset, David Gibson, 2019/08/29
- [Qemu-ppc] [PULL 13/19] target/ppc: Refactor emulation of vmrgew and vmrgow instructions, David Gibson, 2019/08/29
- [Qemu-ppc] [PULL 12/19] target/ppc: Fix do_float_check_status vs inexact, David Gibson, 2019/08/29
- [Qemu-ppc] [PULL 08/19] ppc: Fix xscvdpspn for SNAN, David Gibson, 2019/08/29
- [Qemu-ppc] [PULL 18/19] spapr/pci: Convert types to QEMU coding style, David Gibson, 2019/08/29
- [Qemu-ppc] [PULL 09/19] spapr_pci: remove all child functions in function zero unplug, David Gibson, 2019/08/29
- [Qemu-ppc] [PULL 15/19] powerpc/spapr: Add host threads parameter to ibm, get_system_parameter, David Gibson, 2019/08/29
- [Qemu-ppc] [PULL 19/19] spapr: Set compat mode in spapr_core_plug(), David Gibson, 2019/08/29
- [Qemu-ppc] [PULL 16/19] spapr: Use SHUTDOWN_CAUSE_SUBSYSTEM_RESET for CAS reboots, David Gibson, 2019/08/29
- [Qemu-ppc] [PULL 17/19] spapr_pci: Advertise BAR reallocation capability,
David Gibson <=
- [Qemu-ppc] [PULL 14/19] pseries: Update SLOF firmware image, David Gibson, 2019/08/29