qemu/hw/ppc/spapr_rtas_ddw.c
Alexey Kardashevskiy 8994e91e96 spapr-iommu: Always advertise the maximum possible DMA window size
When deciding about the huge DMA window, the typical Linux pseries guest
uses the maximum allowed RAM size as the upper limit. We did the same
on QEMU side to match that logic. Now we are going to support a GPU RAM
pass through which is not available at the guest boot time as it requires
the guest driver interaction. As the result, the guest requests a smaller
window than it should. Therefore the guest needs to be patched to
understand this new memory and so does QEMU.

Instead of reimplementing here whatever solution we choose for the guest,
this advertises the biggest possible window size limited by 32 bit
(as defined by LoPAPR). Since the window size has to be power-of-two
(the create rtas call receives a window shift, not a size),
this uses 0x8000.0000 as the maximum number of TCEs possible (rather than
32bit maximum of 0xffff.ffff).

This is safe as:
1. The guest visible emulated table is allocated in KVM (actual pages
are allocated in page fault handler) and QEMU (actual pages are allocated
when updated);
2. The hardware table (and corresponding userspace address table)
supports sparse allocation and also checks for locked_vm limit so
it is unable to cause the host any damage.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2018-12-21 09:37:38 +11:00

282 lines
8.2 KiB
C

/*
* QEMU sPAPR Dynamic DMA windows support
*
* Copyright (c) 2015 Alexey Kardashevskiy, IBM Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License,
* or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "cpu.h"
#include "qemu/error-report.h"
#include "hw/ppc/spapr.h"
#include "hw/pci-host/spapr.h"
#include "trace.h"
static int spapr_phb_get_active_win_num_cb(Object *child, void *opaque)
{
sPAPRTCETable *tcet;
tcet = (sPAPRTCETable *) object_dynamic_cast(child, TYPE_SPAPR_TCE_TABLE);
if (tcet && tcet->nb_table) {
++*(unsigned *)opaque;
}
return 0;
}
static unsigned spapr_phb_get_active_win_num(sPAPRPHBState *sphb)
{
unsigned ret = 0;
object_child_foreach(OBJECT(sphb), spapr_phb_get_active_win_num_cb, &ret);
return ret;
}
static int spapr_phb_get_free_liobn_cb(Object *child, void *opaque)
{
sPAPRTCETable *tcet;
tcet = (sPAPRTCETable *) object_dynamic_cast(child, TYPE_SPAPR_TCE_TABLE);
if (tcet && !tcet->nb_table) {
*(uint32_t *)opaque = tcet->liobn;
return 1;
}
return 0;
}
static unsigned spapr_phb_get_free_liobn(sPAPRPHBState *sphb)
{
uint32_t liobn = 0;
object_child_foreach(OBJECT(sphb), spapr_phb_get_free_liobn_cb, &liobn);
return liobn;
}
static uint32_t spapr_page_mask_to_query_mask(uint64_t page_mask)
{
int i;
uint32_t mask = 0;
const struct { int shift; uint32_t mask; } masks[] = {
{ 12, RTAS_DDW_PGSIZE_4K },
{ 16, RTAS_DDW_PGSIZE_64K },
{ 24, RTAS_DDW_PGSIZE_16M },
{ 25, RTAS_DDW_PGSIZE_32M },
{ 26, RTAS_DDW_PGSIZE_64M },
{ 27, RTAS_DDW_PGSIZE_128M },
{ 28, RTAS_DDW_PGSIZE_256M },
{ 34, RTAS_DDW_PGSIZE_16G },
};
for (i = 0; i < ARRAY_SIZE(masks); ++i) {
if (page_mask & (1ULL << masks[i].shift)) {
mask |= masks[i].mask;
}
}
return mask;
}
static void rtas_ibm_query_pe_dma_window(PowerPCCPU *cpu,
sPAPRMachineState *spapr,
uint32_t token, uint32_t nargs,
target_ulong args,
uint32_t nret, target_ulong rets)
{
sPAPRPHBState *sphb;
uint64_t buid;
uint32_t avail, addr, pgmask = 0;
if ((nargs != 3) || (nret != 5)) {
goto param_error_exit;
}
buid = ((uint64_t)rtas_ld(args, 1) << 32) | rtas_ld(args, 2);
addr = rtas_ld(args, 0);
sphb = spapr_pci_find_phb(spapr, buid);
if (!sphb || !sphb->ddw_enabled) {
goto param_error_exit;
}
/* Translate page mask to LoPAPR format */
pgmask = spapr_page_mask_to_query_mask(sphb->page_size_mask);
avail = SPAPR_PCI_DMA_MAX_WINDOWS - spapr_phb_get_active_win_num(sphb);
rtas_st(rets, 0, RTAS_OUT_SUCCESS);
rtas_st(rets, 1, avail);
rtas_st(rets, 2, 0x80000000); /* The largest window we can possibly have */
rtas_st(rets, 3, pgmask);
rtas_st(rets, 4, 0); /* DMA migration mask, not supported */
trace_spapr_iommu_ddw_query(buid, addr, avail, 0x80000000, pgmask);
return;
param_error_exit:
rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
}
static void rtas_ibm_create_pe_dma_window(PowerPCCPU *cpu,
sPAPRMachineState *spapr,
uint32_t token, uint32_t nargs,
target_ulong args,
uint32_t nret, target_ulong rets)
{
sPAPRPHBState *sphb;
sPAPRTCETable *tcet = NULL;
uint32_t addr, page_shift, window_shift, liobn;
uint64_t buid, win_addr;
int windows;
if ((nargs != 5) || (nret != 4)) {
goto param_error_exit;
}
buid = ((uint64_t)rtas_ld(args, 1) << 32) | rtas_ld(args, 2);
addr = rtas_ld(args, 0);
sphb = spapr_pci_find_phb(spapr, buid);
if (!sphb || !sphb->ddw_enabled) {
goto param_error_exit;
}
page_shift = rtas_ld(args, 3);
window_shift = rtas_ld(args, 4);
liobn = spapr_phb_get_free_liobn(sphb);
windows = spapr_phb_get_active_win_num(sphb);
if (!(sphb->page_size_mask & (1ULL << page_shift)) ||
(window_shift < page_shift)) {
goto param_error_exit;
}
if (!liobn || !sphb->ddw_enabled || windows == SPAPR_PCI_DMA_MAX_WINDOWS) {
goto hw_error_exit;
}
tcet = spapr_tce_find_by_liobn(liobn);
if (!tcet) {
goto hw_error_exit;
}
win_addr = (windows == 0) ? sphb->dma_win_addr : sphb->dma64_win_addr;
spapr_tce_table_enable(tcet, page_shift, win_addr,
1ULL << (window_shift - page_shift));
if (!tcet->nb_table) {
goto hw_error_exit;
}
trace_spapr_iommu_ddw_create(buid, addr, 1ULL << page_shift,
1ULL << window_shift, tcet->bus_offset, liobn);
rtas_st(rets, 0, RTAS_OUT_SUCCESS);
rtas_st(rets, 1, liobn);
rtas_st(rets, 2, tcet->bus_offset >> 32);
rtas_st(rets, 3, tcet->bus_offset & ((uint32_t) -1));
return;
hw_error_exit:
rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
return;
param_error_exit:
rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
}
static void rtas_ibm_remove_pe_dma_window(PowerPCCPU *cpu,
sPAPRMachineState *spapr,
uint32_t token, uint32_t nargs,
target_ulong args,
uint32_t nret, target_ulong rets)
{
sPAPRPHBState *sphb;
sPAPRTCETable *tcet;
uint32_t liobn;
if ((nargs != 1) || (nret != 1)) {
goto param_error_exit;
}
liobn = rtas_ld(args, 0);
tcet = spapr_tce_find_by_liobn(liobn);
if (!tcet) {
goto param_error_exit;
}
sphb = SPAPR_PCI_HOST_BRIDGE(OBJECT(tcet)->parent);
if (!sphb || !sphb->ddw_enabled || !tcet->nb_table) {
goto param_error_exit;
}
spapr_tce_table_disable(tcet);
trace_spapr_iommu_ddw_remove(liobn);
rtas_st(rets, 0, RTAS_OUT_SUCCESS);
return;
param_error_exit:
rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
}
static void rtas_ibm_reset_pe_dma_window(PowerPCCPU *cpu,
sPAPRMachineState *spapr,
uint32_t token, uint32_t nargs,
target_ulong args,
uint32_t nret, target_ulong rets)
{
sPAPRPHBState *sphb;
uint64_t buid;
uint32_t addr;
if ((nargs != 3) || (nret != 1)) {
goto param_error_exit;
}
buid = ((uint64_t)rtas_ld(args, 1) << 32) | rtas_ld(args, 2);
addr = rtas_ld(args, 0);
sphb = spapr_pci_find_phb(spapr, buid);
if (!sphb || !sphb->ddw_enabled) {
goto param_error_exit;
}
spapr_phb_dma_reset(sphb);
trace_spapr_iommu_ddw_reset(buid, addr);
rtas_st(rets, 0, RTAS_OUT_SUCCESS);
return;
param_error_exit:
rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
}
static void spapr_rtas_ddw_init(void)
{
spapr_rtas_register(RTAS_IBM_QUERY_PE_DMA_WINDOW,
"ibm,query-pe-dma-window",
rtas_ibm_query_pe_dma_window);
spapr_rtas_register(RTAS_IBM_CREATE_PE_DMA_WINDOW,
"ibm,create-pe-dma-window",
rtas_ibm_create_pe_dma_window);
spapr_rtas_register(RTAS_IBM_REMOVE_PE_DMA_WINDOW,
"ibm,remove-pe-dma-window",
rtas_ibm_remove_pe_dma_window);
spapr_rtas_register(RTAS_IBM_RESET_PE_DMA_WINDOW,
"ibm,reset-pe-dma-window",
rtas_ibm_reset_pe_dma_window);
}
type_init(spapr_rtas_ddw_init)