linux-dev/arch/powerpc/kvm, branch linus/master

powerpc: Fix all occurences of "the the"

2022-05-22T05:59:43Z

Rather than waiting for the bots to fix these one-by-one, fix all occurences of "the the" throughout arch/powerpc. Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220518142629.513007-1-mpe@ellerman.id.au

powerpc: Book3S 64-bit outline-only KASAN support

2022-05-22T05:58:29Z

Implement a limited form of KASAN for Book3S 64-bit machines running under the Radix MMU, supporting only outline mode. - Enable the compiler instrumentation to check addresses and maintain the shadow region. (This is the guts of KASAN which we can easily reuse.) - Require kasan-vmalloc support to handle modules and anything else in vmalloc space. - KASAN needs to be able to validate all pointer accesses, but we can't instrument all kernel addresses - only linear map and vmalloc. On boot, set up a single page of read-only shadow that marks all iomap and vmemmap accesses as valid. - Document KASAN in powerpc docs. Background ---------- KASAN support on Book3S is a bit tricky to get right: - It would be good to support inline instrumentation so as to be able to catch stack issues that cannot be caught with outline mode. - Inline instrumentation requires a fixed offset. - Book3S runs code with translations off ("real mode") during boot, including a lot of generic device-tree parsing code which is used to determine MMU features. [ppc64 mm note: The kernel installs a linear mapping at effective address c000...-c008.... This is a one-to-one mapping with physical memory from 0000... onward. Because of how memory accesses work on powerpc 64-bit Book3S, a kernel pointer in the linear map accesses the same memory both with translations on (accessing as an 'effective address'), and with translations off (accessing as a 'real address'). This works in both guests and the hypervisor. For more details, see s5.7 of Book III of version 3 of the ISA, in particular the Storage Control Overview, s5.7.3, and s5.7.5 - noting that this KASAN implementation currently only supports Radix.] - Some code - most notably a lot of KVM code - also runs with translations off after boot. - Therefore any offset has to point to memory that is valid with translations on or off. One approach is just to give up on inline instrumentation. This way boot-time checks can be delayed until after the MMU is set is up, and we can just not instrument any code that runs with translations off after booting. Take this approach for now and require outline instrumentation. Previous attempts allowed inline instrumentation. However, they came with some unfortunate restrictions: only physically contiguous memory could be used and it had to be specified at compile time. Maybe we can do better in the future. [paulus@ozlabs.org - Rebased onto 5.17. Note that a kernel with CONFIG_KASAN=y will crash during boot on a machine using HPT translation because not all the entry points to the generic KASAN code are protected with a call to kasan_arch_is_ready().] Originally-by: Balbir Singh # ppc64 out-of-line radix version Signed-off-by: Daniel Axtens Signed-off-by: Paul Mackerras [mpe: Update copyright year and comment formatting] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/YoTE69OQwiG7z+Gu@cleo

powerpc: Replace PPC64_ELF_ABI_v{1/2} by CONFIG_PPC64_ELF_ABI_V{1/2}

2022-05-19T13:11:29Z

Replace all uses of PPC64_ELF_ABI_v1 and PPC64_ELF_ABI_v2 by resp CONFIG_PPC64_ELF_ABI_V1 and CONFIG_PPC64_ELF_ABI_V2. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/ba13d59e8c50bc9aa6328f1c7f0c0d0278e0a3a7.1652074503.git.christophe.leroy@csgroup.eu

Merge branch 'topic/ppc-kvm' into next

2022-05-19T13:10:42Z

Merge our KVM topic branch.

KVM: PPC: Book3S HV: Fix vcore_blocked tracepoint

2022-05-18T14:44:50Z

We removed most of the vcore logic from the P9 path but there's still a tracepoint that tried to dereference vc->runner. Fixes: ecb6a7207f92 ("KVM: PPC: Book3S HV P9: Remove most of the vcore logic") Signed-off-by: Fabiano Rosas Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220328215831.320409-1-farosas@linux.ibm.com

KVM: PPC: Book3s: Remove real mode interrupt controller hcalls handlers

2022-05-18T14:44:28Z

Currently we have 2 sets of interrupt controller hypercalls handlers for real and virtual modes, this is from POWER8 times when switching MMU on was considered an expensive operation. POWER9 however does not have dependent threads and MMU is enabled for handling hcalls so the XIVE native or XICS-on-XIVE real mode handlers never execute on real P9 and later CPUs. This untemplate the handlers and only keeps the real mode handlers for XICS native (up to POWER8) and remove the rest of dead code. Changes in functions are mechanical except few missing empty lines to make checkpatch.pl happy. The default implemented hcalls list already contains XICS hcalls so no change there. This should not cause any behavioral change. Reported-by: kernel test robot Signed-off-by: Alexey Kardashevskiy Acked-by: Cédric Le Goater Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220509071150.181250-1-aik@ozlabs.ru

KVM: PPC: Book3s: PR: Enable default TCE hypercalls

2022-05-18T14:44:15Z

When KVM_CAP_PPC_ENABLE_HCALL was introduced, H_GET_TCE and H_PUT_TCE were already implemented and enabled by default; however H_GET_TCE was missed out on PR KVM (probably because the handler was in the real mode code at the time). This enables H_GET_TCE by default. While at this, this wraps the checks in ifdef CONFIG_SPAPR_TCE_IOMMU just like HV KVM. Signed-off-by: Alexey Kardashevskiy Reviewed-by: Fabiano Rosas Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220506073737.3823347-1-aik@ozlabs.ru

KVM: PPC: Book3s: Retire H_PUT_TCE/etc real mode handlers

2022-05-18T14:44:01Z

LoPAPR defines guest visible IOMMU with hypercalls to use it - H_PUT_TCE/etc. Implemented first on POWER7 where hypercalls would trap in the KVM in the real mode (with MMU off). The problem with the real mode is some memory is not available and some API usage crashed the host but enabling MMU was an expensive operation. The problems with the real mode handlers are: 1. Occasionally these cannot complete the request so the code is copied+modified to work in the virtual mode, very little is shared; 2. The real mode handlers have to be linked into vmlinux to work; 3. An exception in real mode immediately reboots the machine. If the small DMA window is used, the real mode handlers bring better performance. However since POWER8, there has always been a bigger DMA window which VMs use to map the entire VM memory to avoid calling H_PUT_TCE. Such 1:1 mapping happens once and uses H_PUT_TCE_INDIRECT (a bulk version of H_PUT_TCE) which virtual mode handler is even closer to its real mode version. On POWER9 hypercalls trap straight to the virtual mode so the real mode handlers never execute on POWER9 and later CPUs. So with the current use of the DMA windows and MMU improvements in POWER9 and later, there is no point in duplicating the code. The 32bit passed through devices may slow down but we do not have many of these in practice. For example, with this applied, a 1Gbit ethernet adapter still demostrates above 800Mbit/s of actual throughput. This removes the real mode handlers from KVM and related code from the powernv platform. This updates the list of implemented hcalls in KVM-HV as the realmode handlers are removed. This changes ABI - kvmppc_h_get_tce() moves to the KVM module and kvmppc_find_table() is static now. Signed-off-by: Alexey Kardashevskiy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220506053755.3820702-1-aik@ozlabs.ru

Merge branch 'fixes' into topic/ppc-kvm

2022-05-18T14:43:04Z

Merge our fixes branch. In parciular this brings in the KVM TCE handling fix, which is a prerequisite for a subsequent patch.

KVM: PPC: Book3S HV: Initialize AMOR in nested entry

2022-05-18T14:28:49Z

The hypervisor always sets AMOR to ~0, but let's ensure we're not passing stale values around. Signed-off-by: Fabiano Rosas Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220425142151.1495142-1-farosas@linux.ibm.com