xref: /openbmc/qemu/hw/ppc/spapr_pci_vfio.c (revision 4dba9141)
1 /*
2  * QEMU sPAPR PCI host for VFIO
3  *
4  * Copyright (c) 2011-2014 Alexey Kardashevskiy, IBM Corporation.
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License,
9  *  or (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include <linux/vfio.h>
22 #include "hw/ppc/spapr.h"
23 #include "hw/pci-host/spapr.h"
24 #include "hw/pci/msix.h"
25 #include "hw/pci/pci_device.h"
26 #include "hw/vfio/vfio.h"
27 #include "qemu/error-report.h"
28 
29 bool spapr_phb_eeh_available(SpaprPhbState *sphb)
30 {
31     return vfio_eeh_as_ok(&sphb->iommu_as);
32 }
33 
34 static void spapr_phb_vfio_eeh_reenable(SpaprPhbState *sphb)
35 {
36     vfio_eeh_as_op(&sphb->iommu_as, VFIO_EEH_PE_ENABLE);
37 }
38 
39 void spapr_phb_vfio_reset(DeviceState *qdev)
40 {
41     /*
42      * The PE might be in frozen state. To reenable the EEH
43      * functionality on it will clean the frozen state, which
44      * ensures that the contained PCI devices will work properly
45      * after reboot.
46      */
47     spapr_phb_vfio_eeh_reenable(SPAPR_PCI_HOST_BRIDGE(qdev));
48 }
49 
50 static void spapr_eeh_pci_find_device(PCIBus *bus, PCIDevice *pdev,
51                                       void *opaque)
52 {
53     bool *found = opaque;
54 
55     if (object_dynamic_cast(OBJECT(pdev), "vfio-pci")) {
56         *found = true;
57     }
58 }
59 
60 int spapr_phb_vfio_eeh_set_option(SpaprPhbState *sphb,
61                                   unsigned int addr, int option)
62 {
63     uint32_t op;
64     int ret;
65 
66     switch (option) {
67     case RTAS_EEH_DISABLE:
68         op = VFIO_EEH_PE_DISABLE;
69         break;
70     case RTAS_EEH_ENABLE: {
71         PCIHostState *phb;
72         bool found = false;
73 
74         /*
75          * The EEH functionality is enabled per sphb level instead of
76          * per PCI device. We have already identified this specific sphb
77          * based on buid passed as argument to ibm,set-eeh-option rtas
78          * call. Now we just need to check the validity of the PCI
79          * pass-through devices (vfio-pci) under this sphb bus.
80          * We have already validated that all the devices under this sphb
81          * are from same iommu group (within same PE) before coming here.
82          *
83          * Prior to linux commit 98ba956f6a389 ("powerpc/pseries/eeh:
84          * Rework device EEH PE determination") kernel would call
85          * eeh-set-option for each device in the PE using the device's
86          * config_address as the argument rather than the PE address.
87          * Hence if we check validity of supplied config_addr whether
88          * it matches to this PHB will cause issues with older kernel
89          * versions v5.9 and older. If we return an error from
90          * eeh-set-option when the argument isn't a valid PE address
91          * then older kernels (v5.9 and older) will interpret that as
92          * EEH not being supported.
93          */
94         phb = PCI_HOST_BRIDGE(sphb);
95         pci_for_each_device(phb->bus, (addr >> 16) & 0xFF,
96                             spapr_eeh_pci_find_device, &found);
97 
98         if (!found) {
99             return RTAS_OUT_PARAM_ERROR;
100         }
101 
102         op = VFIO_EEH_PE_ENABLE;
103         break;
104     }
105     case RTAS_EEH_THAW_IO:
106         op = VFIO_EEH_PE_UNFREEZE_IO;
107         break;
108     case RTAS_EEH_THAW_DMA:
109         op = VFIO_EEH_PE_UNFREEZE_DMA;
110         break;
111     default:
112         return RTAS_OUT_PARAM_ERROR;
113     }
114 
115     ret = vfio_eeh_as_op(&sphb->iommu_as, op);
116     if (ret < 0) {
117         return RTAS_OUT_HW_ERROR;
118     }
119 
120     return RTAS_OUT_SUCCESS;
121 }
122 
123 int spapr_phb_vfio_eeh_get_state(SpaprPhbState *sphb, int *state)
124 {
125     int ret;
126 
127     ret = vfio_eeh_as_op(&sphb->iommu_as, VFIO_EEH_PE_GET_STATE);
128     if (ret < 0) {
129         return RTAS_OUT_PARAM_ERROR;
130     }
131 
132     *state = ret;
133     return RTAS_OUT_SUCCESS;
134 }
135 
136 static void spapr_phb_vfio_eeh_clear_dev_msix(PCIBus *bus,
137                                               PCIDevice *pdev,
138                                               void *opaque)
139 {
140     /* Check if the device is VFIO PCI device */
141     if (!object_dynamic_cast(OBJECT(pdev), "vfio-pci")) {
142         return;
143     }
144 
145     /*
146      * The MSIx table will be cleaned out by reset. We need
147      * disable it so that it can be reenabled properly. Also,
148      * the cached MSIx table should be cleared as it's not
149      * reflecting the contents in hardware.
150      */
151     if (msix_enabled(pdev)) {
152         uint16_t flags;
153 
154         flags = pci_host_config_read_common(pdev,
155                                             pdev->msix_cap + PCI_MSIX_FLAGS,
156                                             pci_config_size(pdev), 2);
157         flags &= ~PCI_MSIX_FLAGS_ENABLE;
158         pci_host_config_write_common(pdev,
159                                      pdev->msix_cap + PCI_MSIX_FLAGS,
160                                      pci_config_size(pdev), flags, 2);
161     }
162 
163     msix_reset(pdev);
164 }
165 
166 static void spapr_phb_vfio_eeh_clear_bus_msix(PCIBus *bus, void *opaque)
167 {
168        pci_for_each_device_under_bus(bus, spapr_phb_vfio_eeh_clear_dev_msix,
169                                      NULL);
170 }
171 
172 static void spapr_phb_vfio_eeh_pre_reset(SpaprPhbState *sphb)
173 {
174        PCIHostState *phb = PCI_HOST_BRIDGE(sphb);
175 
176        pci_for_each_bus(phb->bus, spapr_phb_vfio_eeh_clear_bus_msix, NULL);
177 }
178 
179 int spapr_phb_vfio_eeh_reset(SpaprPhbState *sphb, int option)
180 {
181     uint32_t op;
182     int ret;
183 
184     switch (option) {
185     case RTAS_SLOT_RESET_DEACTIVATE:
186         op = VFIO_EEH_PE_RESET_DEACTIVATE;
187         break;
188     case RTAS_SLOT_RESET_HOT:
189         spapr_phb_vfio_eeh_pre_reset(sphb);
190         op = VFIO_EEH_PE_RESET_HOT;
191         break;
192     case RTAS_SLOT_RESET_FUNDAMENTAL:
193         spapr_phb_vfio_eeh_pre_reset(sphb);
194         op = VFIO_EEH_PE_RESET_FUNDAMENTAL;
195         break;
196     default:
197         return RTAS_OUT_PARAM_ERROR;
198     }
199 
200     ret = vfio_eeh_as_op(&sphb->iommu_as, op);
201     if (ret < 0) {
202         return RTAS_OUT_HW_ERROR;
203     }
204 
205     return RTAS_OUT_SUCCESS;
206 }
207 
208 int spapr_phb_vfio_eeh_configure(SpaprPhbState *sphb)
209 {
210     int ret;
211 
212     ret = vfio_eeh_as_op(&sphb->iommu_as, VFIO_EEH_PE_CONFIGURE);
213     if (ret < 0) {
214         return RTAS_OUT_PARAM_ERROR;
215     }
216 
217     return RTAS_OUT_SUCCESS;
218 }
219