qemu-e2k/hw/spapr_iommu.c
David Gibson 53724ee565 pseries: Rework implementation of TCE bypass
On the pseries machine the IOMMU (aka TCE tables) is always active for all
PCI and VIO devices.  Mostly to simplify the SLOF firmware, we implement an
extension which allows the IOMMU to be temporarily disabled for certain
devices.

Currently this is implemented by setting the device's DMAContext pointer to
NULL (thus reverting to qemu's default no-IOMMU DMA behaviour), then
replacing it when bypass mode is disabled.

This approach causes a bunch of complications though.  It complexifies the
management of the DMAContext lifetimes, it's problematic for savevm/loadvm,
and it means that while bypass is active we have nowhere to store the
device's LIOBN (Logical IO Bus Number, used to identify DMA address
spaces).  At present we regenerate the LIOBN from other address information
but this restricts how we can allocate LIOBNs.

This patch gives up on this approach, replacing it with the much simpler
one of having a 'bypass' boolean flag in the TCE state structure.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
2012-10-04 15:54:18 +02:00

287 lines
7.1 KiB
C

/*
* QEMU sPAPR IOMMU (TCE) code
*
* Copyright (c) 2010 David Gibson, IBM Corporation <dwg@au1.ibm.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "hw.h"
#include "kvm.h"
#include "qdev.h"
#include "kvm_ppc.h"
#include "dma.h"
#include "hw/spapr.h"
#include <libfdt.h>
/* #define DEBUG_TCE */
enum sPAPRTCEAccess {
SPAPR_TCE_FAULT = 0,
SPAPR_TCE_RO = 1,
SPAPR_TCE_WO = 2,
SPAPR_TCE_RW = 3,
};
typedef struct sPAPRTCETable sPAPRTCETable;
struct sPAPRTCETable {
DMAContext dma;
uint32_t liobn;
uint32_t window_size;
sPAPRTCE *table;
bool bypass;
int fd;
QLIST_ENTRY(sPAPRTCETable) list;
};
QLIST_HEAD(spapr_tce_tables, sPAPRTCETable) spapr_tce_tables;
static sPAPRTCETable *spapr_tce_find_by_liobn(uint32_t liobn)
{
sPAPRTCETable *tcet;
QLIST_FOREACH(tcet, &spapr_tce_tables, list) {
if (tcet->liobn == liobn) {
return tcet;
}
}
return NULL;
}
static int spapr_tce_translate(DMAContext *dma,
dma_addr_t addr,
target_phys_addr_t *paddr,
target_phys_addr_t *len,
DMADirection dir)
{
sPAPRTCETable *tcet = DO_UPCAST(sPAPRTCETable, dma, dma);
enum sPAPRTCEAccess access = (dir == DMA_DIRECTION_FROM_DEVICE)
? SPAPR_TCE_WO : SPAPR_TCE_RO;
uint64_t tce;
#ifdef DEBUG_TCE
fprintf(stderr, "spapr_tce_translate liobn=0x%" PRIx32 " addr=0x"
DMA_ADDR_FMT "\n", tcet->liobn, addr);
#endif
if (tcet->bypass) {
*paddr = addr;
*len = (target_phys_addr_t)-1;
return 0;
}
/* Check if we are in bound */
if (addr >= tcet->window_size) {
#ifdef DEBUG_TCE
fprintf(stderr, "spapr_tce_translate out of bounds\n");
#endif
return -EFAULT;
}
tce = tcet->table[addr >> SPAPR_TCE_PAGE_SHIFT].tce;
/* Check TCE */
if (!(tce & access)) {
return -EPERM;
}
/* How much til end of page ? */
*len = ((~addr) & SPAPR_TCE_PAGE_MASK) + 1;
/* Translate */
*paddr = (tce & ~SPAPR_TCE_PAGE_MASK) |
(addr & SPAPR_TCE_PAGE_MASK);
#ifdef DEBUG_TCE
fprintf(stderr, " -> *paddr=0x" TARGET_FMT_plx ", *len=0x"
TARGET_FMT_plx "\n", *paddr, *len);
#endif
return 0;
}
DMAContext *spapr_tce_new_dma_context(uint32_t liobn, size_t window_size)
{
sPAPRTCETable *tcet;
if (!window_size) {
return NULL;
}
tcet = g_malloc0(sizeof(*tcet));
dma_context_init(&tcet->dma, spapr_tce_translate, NULL, NULL);
tcet->liobn = liobn;
tcet->window_size = window_size;
if (kvm_enabled()) {
tcet->table = kvmppc_create_spapr_tce(liobn,
window_size,
&tcet->fd);
}
if (!tcet->table) {
size_t table_size = (window_size >> SPAPR_TCE_PAGE_SHIFT)
* sizeof(sPAPRTCE);
tcet->table = g_malloc0(table_size);
}
#ifdef DEBUG_TCE
fprintf(stderr, "spapr_iommu: New TCE table, liobn=0x%x, context @ %p, "
"table @ %p, fd=%d\n", liobn, &tcet->dma, tcet->table, tcet->fd);
#endif
QLIST_INSERT_HEAD(&spapr_tce_tables, tcet, list);
return &tcet->dma;
}
void spapr_tce_free(DMAContext *dma)
{
if (dma) {
sPAPRTCETable *tcet = DO_UPCAST(sPAPRTCETable, dma, dma);
QLIST_REMOVE(tcet, list);
if (!kvm_enabled() ||
(kvmppc_remove_spapr_tce(tcet->table, tcet->fd,
tcet->window_size) != 0)) {
g_free(tcet->table);
}
g_free(tcet);
}
}
void spapr_tce_set_bypass(DMAContext *dma, bool bypass)
{
sPAPRTCETable *tcet = DO_UPCAST(sPAPRTCETable, dma, dma);
tcet->bypass = bypass;
}
void spapr_tce_reset(DMAContext *dma)
{
sPAPRTCETable *tcet = DO_UPCAST(sPAPRTCETable, dma, dma);
size_t table_size = (tcet->window_size >> SPAPR_TCE_PAGE_SHIFT)
* sizeof(sPAPRTCE);
tcet->bypass = false;
memset(tcet->table, 0, table_size);
}
static target_ulong put_tce_emu(sPAPRTCETable *tcet, target_ulong ioba,
target_ulong tce)
{
sPAPRTCE *tcep;
if (ioba >= tcet->window_size) {
hcall_dprintf("spapr_vio_put_tce on out-of-boards IOBA 0x"
TARGET_FMT_lx "\n", ioba);
return H_PARAMETER;
}
tcep = tcet->table + (ioba >> SPAPR_TCE_PAGE_SHIFT);
tcep->tce = tce;
return H_SUCCESS;
}
static target_ulong h_put_tce(CPUPPCState *env, sPAPREnvironment *spapr,
target_ulong opcode, target_ulong *args)
{
target_ulong liobn = args[0];
target_ulong ioba = args[1];
target_ulong tce = args[2];
sPAPRTCETable *tcet = spapr_tce_find_by_liobn(liobn);
if (liobn & 0xFFFFFFFF00000000ULL) {
hcall_dprintf("spapr_vio_put_tce on out-of-boundsw LIOBN "
TARGET_FMT_lx "\n", liobn);
return H_PARAMETER;
}
ioba &= ~(SPAPR_TCE_PAGE_SIZE - 1);
if (tcet) {
return put_tce_emu(tcet, ioba, tce);
}
#ifdef DEBUG_TCE
fprintf(stderr, "%s on liobn=" TARGET_FMT_lx /*%s*/
" ioba 0x" TARGET_FMT_lx " TCE 0x" TARGET_FMT_lx "\n",
__func__, liobn, /*dev->qdev.id, */ioba, tce);
#endif
return H_PARAMETER;
}
void spapr_iommu_init(void)
{
QLIST_INIT(&spapr_tce_tables);
/* hcall-tce */
spapr_register_hypercall(H_PUT_TCE, h_put_tce);
}
int spapr_dma_dt(void *fdt, int node_off, const char *propname,
uint32_t liobn, uint64_t window, uint32_t size)
{
uint32_t dma_prop[5];
int ret;
dma_prop[0] = cpu_to_be32(liobn);
dma_prop[1] = cpu_to_be32(window >> 32);
dma_prop[2] = cpu_to_be32(window & 0xFFFFFFFF);
dma_prop[3] = 0; /* window size is 32 bits */
dma_prop[4] = cpu_to_be32(size);
ret = fdt_setprop_cell(fdt, node_off, "ibm,#dma-address-cells", 2);
if (ret < 0) {
return ret;
}
ret = fdt_setprop_cell(fdt, node_off, "ibm,#dma-size-cells", 2);
if (ret < 0) {
return ret;
}
ret = fdt_setprop(fdt, node_off, propname, dma_prop, sizeof(dma_prop));
if (ret < 0) {
return ret;
}
return 0;
}
int spapr_tcet_dma_dt(void *fdt, int node_off, const char *propname,
DMAContext *iommu)
{
if (!iommu) {
return 0;
}
if (iommu->translate == spapr_tce_translate) {
sPAPRTCETable *tcet = DO_UPCAST(sPAPRTCETable, dma, iommu);
return spapr_dma_dt(fdt, node_off, propname,
tcet->liobn, 0, tcet->window_size);
}
return -1;
}