tests/functional/test_mem_addr_space.py

19     # the VM generates empty logs. A delay of 1 second is added for
21     DELAY_Q35_BOOT_SEQUENCE = 1
35             # bits == 1 -> 32-bit; bits == 2 -> 64-bit
36             bits = int.from_bytes(fh.read(1), byteorder='little')
47         access up to a maximum of 64GiB of memory. Memory hotplug region begins
48         at 4 GiB boundary when "above_4g_mem_size" is 0 (this would be true when
49         we have 0.5 GiB of VM memory, see pc_q35_init()). This means total
50         hotpluggable memory size is 60 GiB. Per slot, we reserve 1 GiB of memory
52         actual memory size of 59 GiB. If the VM is started with 0.5 GiB of
53         memory, maxmem should be set to a maximum value of 59.5 GiB to ensure
62                          '512,slots=1,maxmem=59.6G',
64                          '-object', 'memory-backend-ram,id=mem1,size=1G',
69         self.assertEqual(self.vm.exitcode(), 1, "QEMU exit code should be 1")
75         access up to a maximum of 64GiB of memory. Rest is the same as the case
80                          '512,slots=1,maxmem=59.6G',
82                          '-object', 'memory-backend-ram,id=mem1,size=1G',
87         self.assertEqual(self.vm.exitcode(), 1, "QEMU exit code should be 1")
97                          '512,slots=1,maxmem=59.5G',
99                          '-object', 'memory-backend-ram,id=mem1,size=1G',
115                          '512,slots=1,maxmem=59.5G',
117                          '-object', 'memory-backend-ram,id=mem1,size=1G',
132                          '512,slots=1,maxmem=59.5G',
134                          '-object', 'memory-backend-ram,id=mem1,size=1G',
145         so it can access physical address up to 4 GiB. Setting maxmem to
146         4 GiB should make QEMU fail to start with "phys-bits too low"
148         above 4 GiB due to the PCI hole and simplicity.
152                          '512,slots=1,maxmem=4G',
154                          '-object', 'memory-backend-ram,id=mem1,size=1G',
159         self.assertEqual(self.vm.exitcode(), 1, "QEMU exit code should be 1")
166         1024 GiB and ends at 1 TiB - 1. If the max GPA falls in this range,
167         "above_4G" memory is adjusted to start at 1 TiB boundary for AMD cpus
170         pci64_hole size is 32 GiB. Since TCG_PHYS_ADDR_BITS is defined to
171         be 40, TCG emulated CPUs have maximum of 1 TiB (1024 GiB) of
174         1024 GiB - 4 GiB - 1 GiB per slot for alignment - 32 GiB + 0.5 GiB
175         which is equal to 987.5 GiB. Setting the value to 988 GiB should
180                          '512,slots=1,maxmem=988G',
182                          '-object', 'memory-backend-ram,id=mem1,size=1G',
187         self.assertEqual(self.vm.exitcode(), 1, "QEMU exit code should be 1")
192         AMD_HT_START is defined to be at 1012 GiB. So for q35 machines
193         version > 7.0 and AMD cpus, instead of 1024 GiB limit for 40 bit
194         processor address space, it has to be 1012 GiB , that is 12 GiB
196         Make sure QEMU fails when maxmem size is 976 GiB (12 GiB less
197         than 988 GiB).
201                          '512,slots=1,maxmem=976G',
203                          '-object', 'memory-backend-ram,id=mem1,size=1G',
208         self.assertEqual(self.vm.exitcode(), 1, "QEMU exit code should be 1")
218                          '512,slots=1,maxmem=987.5G',
220                          '-object', 'memory-backend-ram,id=mem1,size=1G',
235                          '512,slots=1,maxmem=975.5G',
237                          '-object', 'memory-backend-ram,id=mem1,size=1G',
254                          '512,slots=1,maxmem=976G',
256                          '-object', 'memory-backend-ram,id=mem1,size=1G',
267         By setting maxram above 1012 GiB  - 32 GiB - 4 GiB = 976 GiB, we can
268         force "above_4G" memory to start at 1 TiB for q35-7.1 machines
269         (max GPA will be above AMD_HT_START which is defined as 1012 GiB).
271         With pci_64_hole size at 32 GiB, in this case, maxmem should be 991.5
272         GiB with 1 GiB per slot for alignment and 0.5 GiB as non-hotplug
273         memory for the VM (1024 - 32 - 1 + 0.5). With 992 GiB, QEMU should
279                          '512,slots=1,maxmem=992G',
281                          '-object', 'memory-backend-ram,id=mem1,size=1G',
286         self.assertEqual(self.vm.exitcode(), 1, "QEMU exit code should be 1")
292         Same as above but by setting maxram between 976 GiB and 992 Gib,
298                          '512,slots=1,maxmem=990G',
300                          '-object', 'memory-backend-ram,id=mem1,size=1G',
310         cxl memory window starts after memory device range. Here, we use 1 GiB
311         of cxl window memory. 4G_mem end aligns at 4G. pci64_hole is 32 GiB and
313         So maxmem here should be at most 986 GiB considering all memory boundary
314         alignment constraints with 40 bits (1 TiB) of processor physical bits.
319                          '512,slots=1,maxmem=987G',
321                          '-device', 'pxb-cxl,bus_nr=12,bus=pcie.0,id=cxl.1',
322                          '-M', 'cxl-fmw.0.targets.0=cxl.1,cxl-fmw.0.size=1G')
326         self.assertEqual(self.vm.exitcode(), 1, "QEMU exit code should be 1")
338                          '512,slots=1,maxmem=987G',
340                          '-device', 'pxb-cxl,bus_nr=12,bus=pcie.0,id=cxl.1')