linux/arch/powerpc/kvm
Nicholas Piggin 5088eb4092 KVM: PPC: Book3S HV P9: Restore host CTRL SPR after guest exit
The host CTRL (runlatch) value is not restored after guest exit. The
host CTRL should always be 1 except in CPU idle code, so this can result
in the host running with runlatch clear, and potentially switching to
a different vCPU which then runs with runlatch clear as well.

This has little effect on P9 machines, CTRL is only responsible for some
PMU counter logic in the host and so other than corner cases of software
relying on that, or explicitly reading the runlatch value (Linux does
not appear to be affected but it's possible non-Linux guests could be),
there should be no execution correctness problem, though it could be
used as a covert channel between guests.

There may be microcontrollers, firmware or monitoring tools that sample
the runlatch value out-of-band, however since the register is writable
by guests, these values would (should) not be relied upon for correct
operation of the host, so suboptimal performance or incorrect reporting
should be the worst problem.

Fixes: 95a6432ce9 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210412014845.1517916-2-npiggin@gmail.com
2021-04-12 13:36:22 +10:00
..
book3s_32_mmu_host.c KVM: PPC: Book3S PR: Move kvmppc_mmu_init() into PR KVM 2020-03-19 16:39:52 +11:00
book3s_32_mmu.c KVM: PPC: Use fallthrough; 2020-03-19 16:39:52 +11:00
book3s_32_sr.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_64_mmu_host.c KVM: PPC: Book3S PR: Move kvmppc_mmu_init() into PR KVM 2020-03-19 16:39:52 +11:00
book3s_64_mmu_hv.c x86: 2021-02-26 10:00:12 -08:00
book3s_64_mmu_radix.c KVM: x86/mmu: Consider the hva in mmu_notifier retry 2021-02-22 13:16:53 -05:00
book3s_64_mmu.c KVM: PPC: Use fallthrough; 2020-03-19 16:39:52 +11:00
book3s_64_slb.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_64_vio_hv.c treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
book3s_64_vio.c KVM: PPC: Book3S: Fix symbol undeclared warnings 2020-09-22 11:53:55 +10:00
book3s_emulate.c powerpc/32s: Change mfsrin() into a static inline function 2021-02-09 01:10:15 +11:00
book3s_exports.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_hv_builtin.c powerpc updates for 5.12 2021-02-22 14:34:00 -08:00
book3s_hv_hmi.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 114 2019-05-24 17:39:01 +02:00
book3s_hv_interrupts.S KVM: PPC: Book3S HV: Set LPCR[HDICE] before writing HDEC 2020-09-17 11:38:17 +10:00
book3s_hv_nested.c KVM: PPC: Book3S HV: Add infrastructure to support 2nd DAWR 2021-02-10 14:31:08 +11:00
book3s_hv_ras.c KVM: PPC: Book3S HV: Don't attempt to recover machine checks for FWNMI enabled guests 2020-12-04 01:01:23 +11:00
book3s_hv_rm_mmu.c powerpc: Define new SRR1 bits for a ISA v3.1 2020-05-19 00:10:38 +10:00
book3s_hv_rm_xics.c KVM: PPC: Book3S: Fix symbol undeclared warnings 2020-09-22 11:53:55 +10:00
book3s_hv_rm_xive.c mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
book3s_hv_rmhandlers.S KVM: PPC: Book3S HV: Fix host radix SLB optimisation with hash guests 2021-02-11 17:28:15 +11:00
book3s_hv_tm_builtin.c KVM: PPC: Book3S HV: Treat TM-related invalid form instructions on P9 like the valid ones 2020-03-19 16:39:52 +11:00
book3s_hv_tm.c KVM: PPC: Book3S HV: Treat TM-related invalid form instructions on P9 like the valid ones 2020-03-19 16:39:52 +11:00
book3s_hv_uvmem.c mm/memremap_pages: support multiple ranges per invocation 2020-10-13 18:38:28 -07:00
book3s_hv.c KVM: PPC: Book3S HV P9: Restore host CTRL SPR after guest exit 2021-04-12 13:36:22 +10:00
book3s_interrupts.S PPC KVM update for 5.9 2020-08-09 13:24:02 -04:00
book3s_mmu_hpte.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
book3s_paired_singles.c KVM: PPC: Clean up redundant 'kvm_run' parameters 2020-05-27 11:39:31 +10:00
book3s_pr_papr.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
book3s_pr.c powerpc/64s: Remove MSR[ISF] bit 2020-12-09 23:48:14 +11:00
book3s_rmhandlers.S powerpc: Replace RFI by rfi on book3s/32 and booke 2020-11-19 16:56:54 +11:00
book3s_rtas.c KVM: PPC: Protect kvm_vcpu_read_guest with srcu locks 2020-07-21 15:38:03 +10:00
book3s_segment.S powerpc/64s/exception: Move KVM test to common code 2020-04-01 13:42:11 +11:00
book3s_xics.c KVM: PPC: Book3S: Assign boolean values to a bool variable 2020-12-15 22:22:06 +11:00
book3s_xics.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
book3s_xive_native.c powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_SHIFT_BUG 2020-12-11 09:53:10 +11:00
book3s_xive_template.c powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_EOI_FW 2020-12-11 09:53:10 +11:00
book3s_xive.c powerpc/xive: Assign boolean values to a bool variable 2021-02-11 23:35:06 +11:00
book3s_xive.h KVM: PPC: Book3S HV: XIVE: Add a comment regarding VP numbering 2020-12-11 09:53:11 +11:00
book3s.c KVM: PPC: Don't return -ENOTSUPP to userspace in ioctls 2020-09-17 11:38:17 +10:00
book3s.h KVM: PPC: Clean up redundant 'kvm_run' parameters 2020-05-27 11:39:31 +10:00
booke_emulate.c KVM: PPC: Clean up redundant 'kvm_run' parameters 2020-05-27 11:39:31 +10:00
booke_interrupts.S KVM: PPC: Clean up redundant kvm_run parameters in assembly 2020-07-23 15:50:01 +10:00
booke.c powerpc updates for 5.12 2021-02-22 14:34:00 -08:00
booke.h KVM: PPC: Clean up redundant 'kvm_run' parameters 2020-05-27 11:39:31 +10:00
bookehv_interrupts.S KVM: PPC: Clean up redundant kvm_run parameters in assembly 2020-07-23 15:50:01 +10:00
e500_emulate.c KVM: PPC: Clean up redundant 'kvm_run' parameters 2020-05-27 11:39:31 +10:00
e500_mmu_host.c KVM: Pass MMU notifier range flags to kvm_unmap_hva_range() 2020-08-21 18:03:47 -04:00
e500_mmu_host.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
e500_mmu.c KVM: PPC: Kill kvmppc_ops::mmu_destroy() and kvmppc_mmu_destroy() 2020-03-19 16:43:07 +11:00
e500.c KVM: PPC: Kill kvmppc_ops::mmu_destroy() and kvmppc_mmu_destroy() 2020-03-19 16:43:07 +11:00
e500.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
e500mc.c KVM: PPC: Kill kvmppc_ops::mmu_destroy() and kvmppc_mmu_destroy() 2020-03-19 16:43:07 +11:00
emulate_loadstore.c MIPS: 2020-06-12 11:05:52 -07:00
emulate.c KVM: PPC: Clean up redundant 'kvm_run' parameters 2020-05-27 11:39:31 +10:00
fpu.S mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
irq.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig powerpc/kvm: Force selection of CONFIG_PPC_FPU 2021-01-30 11:39:32 +11:00
Makefile KVM: PPC: Book3S HV: Support for running secure guests 2019-11-28 16:30:02 +11:00
mpic.c KVM: Remove unnecessary asm/kvm_host.h includes 2020-03-16 17:57:34 +01:00
powerpc.c powerpc updates for 5.12 2021-02-22 14:34:00 -08:00
timing.c powerpc/kvm: no need to check return value of debugfs_create functions 2020-03-04 22:44:25 +11:00
timing.h KVM: Remove unnecessary asm/kvm_host.h includes 2020-03-16 17:57:34 +01:00
tm.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
trace_book3s.h KVM: PPC: Book3S: Simplify external interrupt handling 2018-10-09 16:04:27 +11:00
trace_booke.h KVM: PPC: Move and undef TRACE_INCLUDE_PATH/FILE 2018-11-07 23:04:38 +11:00
trace_hv.h KVM: PPC: Fix typo on H_DISABLE_AND_GET hcall 2020-07-23 17:43:35 +10:00
trace_pr.h KVM: PPC: Move and undef TRACE_INCLUDE_PATH/FILE 2018-11-07 23:04:38 +11:00
trace.h KVM: PPC: Move and undef TRACE_INCLUDE_PATH/FILE 2018-11-07 23:04:38 +11:00