- 28 Sep, 2020 27 commits
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Maxim Levitsky authored
MSR reads/writes should always access the L1 state, since the (nested) hypervisor should intercept all the msrs it wants to adjust, and these that it doesn't should be read by the guest as if the host had read it. However IA32_TSC is an exception. Even when not intercepted, guest still reads the value + TSC offset. The write however does not take any TSC offset into account. This is documented in Intel's SDM and seems also to happen on AMD as well. This creates a problem when userspace wants to read the IA32_TSC value and then write it. (e.g for migration) In this case it reads L2 value but write is interpreted as an L1 value. To fix this make the userspace initiated reads of IA32_TSC return L1 value as well. Huge thanks to Dave Gilbert for helping me understand this very confusing semantic of MSR writes. Signed-off-by:
Maxim Levitsky <mlevitsk@redhat.com> Message-Id: <20200921103805.9102-2-mlevitsk@redhat.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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Rustam Kovhaev authored
Make use of the struct_size() helper to avoid any potential type mistakes and protect against potential integer overflows Make use of the flex_array_size() helper to calculate the size of a flexible array member within an enclosing structure Suggested-by:
Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by:
Rustam Kovhaev <rkovhaev@gmail.com> Message-Id: <20200918120500.954436-1-rkovhaev@gmail.com> Reviewed-by:
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Babu Moger authored
The following intercept bit has been added to support VMEXIT for INVPCID instruction: Code Name Cause A2h VMEXIT_INVPCID INVPCID instruction The following bit has been added to the VMCB layout control area to control intercept of INVPCID: Byte Offset Bit(s) Function 14h 2 intercept INVPCID Enable the interceptions when the the guest is running with shadow page table enabled and handle the tlbflush based on the invpcid instruction type. For the guests with nested page table (NPT) support, the INVPCID feature works as running it natively. KVM does not need to do any special handling in this case. AMD documentation for INVPCID feature is available at "AMD64 Architecture Programmer’s Manual Volume 2: System Programming, Pub. 24593 Rev. 3.34(or later)" The documentation can be obtained at the links below: Link: https://www.amd.com/system/files/TechDocs/24593.pdf Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537Signed-off-by:
Babu Moger <babu.moger@amd.com> Reviewed-by:
Jim Mattson <jmattson@google.com> Message-Id: <159985255929.11252.17346684135277453258.stgit@bmoger-ubuntu> Signed-off-by:
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Babu Moger authored
INVPCID instruction handling is mostly same across both VMX and SVM. So, move the code to common x86.c. Signed-off-by:
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Babu Moger authored
Handling of kvm_read/write_guest_virt*() errors can be moved to common code. The same code can be used by both VMX and SVM. Signed-off-by:
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Babu Moger authored
Remove set_cr_intercept, clr_cr_intercept and is_cr_intercept. Instead call generic svm_set_intercept, svm_clr_intercept an dsvm_is_intercep tfor all cr intercepts. Signed-off-by:
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Babu Moger authored
The new intercept bits have been added in vmcb control area to support few more interceptions. Here are the some of them. - INTERCEPT_INVLPGB, - INTERCEPT_INVLPGB_ILLEGAL, - INTERCEPT_INVPCID, - INTERCEPT_MCOMMIT, - INTERCEPT_TLBSYNC, Add a new intercept word in vmcb_control_area to support these instructions. Also update kvm_nested_vmrun trace function to support the new addition. AMD documentation for these instructions is available at "AMD64 Architecture Programmer’s Manual Volume 2: System Programming, Pub. 24593 Rev. 3.34(or later)" The documentation can be obtained at the links below: Link: https://www.amd.com/system/files/TechDocs/24593.pdf Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537Signed-off-by:
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Babu Moger authored
Convert all the intercepts to one array of 32 bit vectors in vmcb_control_area. This makes it easy for future intercept vector additions. Also update trace functions. Signed-off-by:
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Babu Moger authored
Modify intercept_exceptions to generic intercepts in vmcb_control_area. Use the generic vmcb_set_intercept, vmcb_clr_intercept and vmcb_is_intercept to set/clear/test the intercept_exceptions bits. Signed-off-by:
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Babu Moger authored
Modify intercept_dr to generic intercepts in vmcb_control_area. Use the generic vmcb_set_intercept, vmcb_clr_intercept and vmcb_is_intercept to set/clear/test the intercept_dr bits. Signed-off-by:
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Babu Moger authored
Change intercept_cr to generic intercepts in vmcb_control_area. Use the new vmcb_set_intercept, vmcb_clr_intercept and vmcb_is_intercept where applicable. Signed-off-by:
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Babu Moger authored
This is in preparation for the future intercept vector additions. Add new functions vmcb_set_intercept, vmcb_clr_intercept and vmcb_is_intercept using kernel APIs __set_bit, __clear_bit and test_bit espectively. Signed-off-by:
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Babu Moger authored
host_intercept_exceptions is not used anywhere. Clean it up. Signed-off-by:
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Maxim Levitsky authored
Kernel coding style suggests not to use labels like error1,error2 Suggested-by:
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Maxim Levitsky authored
Another small refactoring. Suggested-by:
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Maxim Levitsky authored
Replace svm_vcpu_init_msrpm with svm_vcpu_alloc_msrpm, that also allocates the msr bitmap and add svm_vcpu_free_msrpm to free it. This will be used later to move the nested msr permission bitmap allocation to nested.c Signed-off-by:
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Maxim Levitsky authored
This is to be more consistient with VMX, and to support upcoming addition of vmcb02 Hopefully no functional changes. Signed-off-by:
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Maxim Levitsky authored
The 'page' is to hold the vcpu's vmcb so name it as such to avoid confusion. Signed-off-by:
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Wanpeng Li authored
All the checks in lapic_timer_int_injected(), __kvm_wait_lapic_expire(), and these function calls waste cpu cycles when the timer mode is not tscdeadline. We can observe ~1.3% world switch time overhead by kvm-unit-tests/vmexit.flat vmcall testing on AMD server. This patch reduces the world switch latency caused by timer_advance_ns feature when the timer mode is not tscdeadline by simpling move the check against apic->lapic_timer.expired_tscdeadline much earlier. Signed-off-by:
Wanpeng Li <wanpengli@tencent.com> Message-Id: <1599731444-3525-7-git-send-email-wanpengli@tencent.com> Signed-off-by:
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Wanpeng Li authored
The kick after setting KVM_REQ_PENDING_TIMER is used to handle the timer fires on a different pCPU which vCPU is running on. This kick costs about 1000 clock cycles and we don't need this when injecting already-expired timer or when using the VMX preemption timer because kvm_lapic_expired_hv_timer() is called from the target vCPU. Reviewed-by:
Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by:
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Wanpeng Li authored
Check apic_lvtt_tscdeadline() mode directly instead of apic_lvtt_oneshot() and apic_lvtt_period() to guarantee the timer is in tsc-deadline mode when wrmsr MSR_IA32_TSCDEADLINE. Reviewed-by:
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Wanpeng Li authored
Return 0 when getting the tscdeadline timer if the lapic is hw disabled. Suggested-by:
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Wanpeng Li authored
There is missing apic map recalculation after updating DFR, if it is INIT RESET, in x2apic mode, local apic is software enabled before. This patch fix it by introducing the function kvm_apic_set_dfr() to be called in INIT RESET handling path. Signed-off-by:
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Yi Li authored
There is no need to calculate wildcard in each iteration since wildcard is not changed. Signed-off-by:
Yi Li <yili@winhong.com> Message-Id: <20200911055652.3041762-1-yili@winhong.com> Signed-off-by:
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Chenyi Qiang authored
The nested VMX controls MSRs can be initialized by the global capability values stored in vmcs_config. Signed-off-by:
Chenyi Qiang <chenyi.qiang@intel.com> Reviewed-by:
Xiaoyao Li <xiaoyao.li@intel.com> Message-Id: <20200828085622.8365-6-chenyi.qiang@intel.com> Signed-off-by:
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Chenyi Qiang authored
KVM supports the nested VM_{EXIT, ENTRY}_LOAD_IA32_PERF_GLOBAL_CTRL and VM_{ENTRY_LOAD, EXIT_CLEAR}_BNDCFGS, but they are not exposed by the system ioctl KVM_GET_MSR. Add them to the setup of nested VMX controls MSR. Signed-off-by: -
Vitaly Kuznetsov authored
The save and ctl pointers are passed uninitialized to kfree() when svm_set_nested_state() follows the 'goto out_set_gif' path. While the issue could've been fixed by initializing these on-stack varialbles to NULL, it seems preferable to eliminate 'out_set_gif' label completely as it is not actually a failure path and duplicating a single svm_set_gif() call doesn't look too bad. [ bp: Drop obscure Addresses-Coverity: tag. ] Fixes: 6ccbd29a ("KVM: SVM: nested: Don't allocate VMCB structures on stack") Reported-by:
Dan Carpenter <dan.carpenter@oracle.com> Reported-by:
Joerg Roedel <jroedel@suse.de> Reported-by:
Colin King <colin.king@canonical.com> Signed-off-by:
Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by:
Borislav Petkov <bp@suse.de> Reviewed-by:
Tom Lendacky <thomas.lendacky@amd.com> Link: https://lkml.kernel.org/r/20200914133725.650221-1-vkuznets@redhat.comSigned-off-by:
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- 22 Sep, 2020 5 commits
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Paolo Bonzini authored
Merge tag 'kvm-ppc-next-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD PPC KVM update for 5.10 - Fix for running nested guests with in-kernel IRQ chip - Fix race condition causing occasional host hard lockup - Minor cleanups and bugfixes
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Paolo Bonzini authored
Merge branch 'x86-seves-for-paolo' of https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into HEAD
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Wang Wensheng authored
Build the kernel with `C=2`: arch/powerpc/kvm/book3s_hv_nested.c:572:25: warning: symbol 'kvmhv_alloc_nested' was not declared. Should it be static? arch/powerpc/kvm/book3s_64_mmu_radix.c:350:6: warning: symbol 'kvmppc_radix_set_pte_at' was not declared. Should it be static? arch/powerpc/kvm/book3s_hv.c:3568:5: warning: symbol 'kvmhv_p9_guest_entry' was not declared. Should it be static? arch/powerpc/kvm/book3s_hv_rm_xics.c:767:15: warning: symbol 'eoi_rc' was not declared. Should it be static? arch/powerpc/kvm/book3s_64_vio_hv.c:240:13: warning: symbol 'iommu_tce_kill_rm' was not declared. Should it be static? arch/powerpc/kvm/book3s_64_vio.c:492:6: warning: symbol 'kvmppc_tce_iommu_do_map' was not declared. Should it be static? arch/powerpc/kvm/book3s_pr.c:572:6: warning: symbol 'kvmppc_set_pvr_pr' was not declared. Should it be static? Those symbols are used only in the files that define them so make them static to fix the warnings. Signed-off-by:
Wang Wensheng <wangwensheng4@huawei.com> Signed-off-by:
Paul Mackerras <paulus@ozlabs.org>
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Jing Xiangfeng authored
The variable ret is being initialized with '-ENOMEM' that is meaningless. So remove it. Signed-off-by:
Jing Xiangfeng <jingxiangfeng@huawei.com> Reviewed-by:
Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by:
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Qinglang Miao authored
Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code. Signed-off-by:
Qinglang Miao <miaoqinglang@huawei.com> Reviewed-by:
Cédric Le Goater <clg@kaod.org> Signed-off-by:
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- 20 Sep, 2020 3 commits
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Paolo Bonzini authored
Merge tag 'kvm-s390-master-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into kvm-master KVM: s390: add documentation for KVM_CAP_S390_DIAG318 diag318 code was merged in 5.9-rc1, let us add some missing documentation
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Paolo Bonzini authored
Merge tag 'kvmarm-fixes-5.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master KVM/arm64 fixes for 5.9, take #2 - Fix handling of S1 Page Table Walk permission fault at S2 on instruction fetch - Cleanup kvm_vcpu_dabt_iswrite()
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Vitaly Kuznetsov authored
The commit 0f990222 ("KVM: Check the allocation of pv cpu mask") we have in 5.9-rc5 has two issue: 1) Compilation fails for !CONFIG_SMP, see: https://bugzilla.kernel.org/show_bug.cgi?id=209285 2) This commit completely disables PV TLB flush, see https://lore.kernel.org/kvm/87y2lrnnyf.fsf@vitty.brq.redhat.com/ The allocation problem is likely a theoretical one, if we don't have memory that early in boot process we're likely doomed anyway. Let's solve it properly later. This reverts commit 0f990222. Signed-off-by:
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- 18 Sep, 2020 2 commits
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Marc Zyngier authored
Now that kvm_vcpu_trap_is_write_fault() checks for S1PTW, there is no need for kvm_vcpu_dabt_iswrite() to do the same thing, as we already check for this condition on all existing paths. Drop the check and add a comment instead. Signed-off-by:
Marc Zyngier <maz@kernel.org> Reviewed-by:
Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200915104218.1284701-3-maz@kernel.org
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Marc Zyngier authored
KVM currently assumes that an instruction abort can never be a write. This is in general true, except when the abort is triggered by a S1PTW on instruction fetch that tries to update the S1 page tables (to set AF, for example). This can happen if the page tables have been paged out and brought back in without seeing a direct write to them (they are thus marked read only), and the fault handling code will make the PT executable(!) instead of writable. The guest gets stuck forever. In these conditions, the permission fault must be considered as a write so that the Stage-1 update can take place. This is essentially the I-side equivalent of the problem fixed by 60e21a0e ("arm64: KVM: Take S1 walks into account when determining S2 write faults"). Update kvm_is_write_fault() to return true on IABT+S1PTW, and introduce kvm_vcpu_trap_is_exec_fault() that only return true when no faulting on a S1 fault. Additionally, kvm_vcpu_dabt_iss1tw() is renamed to kvm_vcpu_abt_iss1tw(), as the above makes it plain that it isn't specific to data abort. Signed-off-by:
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- 17 Sep, 2020 3 commits
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Paul Mackerras authored
POWER8 and POWER9 machines have a hardware deviation where generation of a hypervisor decrementer exception is suppressed if the HDICE bit in the LPCR register is 0 at the time when the HDEC register decrements from 0 to -1. When entering a guest, KVM first writes the HDEC register with the time until it wants the CPU to exit the guest, and then writes the LPCR with the guest value, which includes HDICE = 1. If HDEC decrements from 0 to -1 during the interval between those two events, it is possible that we can enter the guest with HDEC already negative but no HDEC exception pending, meaning that no HDEC interrupt will occur while the CPU is in the guest, or at least not until HDEC wraps around. Thus it is possible for the CPU to keep executing in the guest for a long time; up to about 4 seconds on POWER8, or about 4.46 years on POWER9 (except that the host kernel hard lockup detector will fire first). To fix this, we set the LPCR[HDICE] bit before writing HDEC on guest entry. Signed-off-by: -
Fabiano Rosas authored
The current nested KVM code does not support HPT guests. This is informed/enforced in some ways: - Hosts < P9 will not be able to enable the nested HV feature; - The nested hypervisor MMU capabilities will not contain KVM_CAP_PPC_MMU_HASH_V3; - QEMU reflects the MMU capabilities in the 'ibm,arch-vec-5-platform-support' device-tree property; - The nested guest, at 'prom_parse_mmu_model' ignores the 'disable_radix' kernel command line option if HPT is not supported; - The KVM_PPC_CONFIGURE_V3_MMU ioctl will fail if trying to use HPT. There is, however, still a way to start a HPT guest by using max-compat-cpu=power8 at the QEMU machine options. This leads to the guest being set to use hash after QEMU calls the KVM_PPC_ALLOCATE_HTAB ioctl. With the guest set to hash, the nested hypervisor goes through the entry path that has no knowledge of nesting (kvmppc_run_vcpu) and crashes when it tries to execute an hypervisor-privileged (mtspr HDEC) instruction at __kvmppc_vcore_entry: root@L1:~ $ qemu-system-ppc64 -machine pseries,max-cpu-compat=power8 ... <snip> [ 538.543303] CPU: 83 PID: 25185 Comm: CPU 0/KVM Not tainted 5.9.0-rc4 #1 [ 538.543355] NIP: c00800000753f388 LR: c00800000753f368 CTR: c0000000001e5ec0 [ 538.543417] REGS: c0000013e91e33b0 TRAP: 0700 Not tainted (5.9.0-rc4) [ 538.543470] MSR: 8000000002843033 <SF,VEC,VSX,FP,ME,IR,DR,RI,LE> CR: 22422882 XER: 20040000 [ 538.543546] CFAR: c00800000753f4b0 IRQMASK: 3 GPR00: c0080000075397a0 c0000013e91e3640 c00800000755e600 0000000080000000 GPR04: 0000000000000000 c0000013eab19800 c000001394de0000 00000043a054db72 GPR08: 00000000003b1652 0000000000000000 0000000000000000 c0080000075502e0 GPR12: c0000000001e5ec0 c0000007ffa74200 c0000013eab19800 0000000000000008 GPR16: 0000000000000000 c00000139676c6c0 c000000001d23948 c0000013e91e38b8 GPR20: 0000000000000053 0000000000000000 0000000000000001 0000000000000000 GPR24: 0000000000000001 0000000000000001 0000000000000000 0000000000000001 GPR28: 0000000000000001 0000000000000053 c0000013eab19800 0000000000000001 [ 538.544067] NIP [c00800000753f388] __kvmppc_vcore_entry+0x90/0x104 [kvm_hv] [ 538.544121] LR [c00800000753f368] __kvmppc_vcore_entry+0x70/0x104 [kvm_hv] [ 538.544173] Call Trace: [ 538.544196] [c0000013e91e3640] [c0000013e91e3680] 0xc0000013e91e3680 (unreliable) [ 538.544260] [c0000013e91e3820] [c0080000075397a0] kvmppc_run_core+0xbc8/0x19d0 [kvm_hv] [ 538.544325] [c0000013e91e39e0] [c00800000753d99c] kvmppc_vcpu_run_hv+0x404/0xc00 [kvm_hv] [ 538.544394] [c0000013e91e3ad0] [c0080000072da4fc] kvmppc_vcpu_run+0x34/0x48 [kvm] [ 538.544472] [c0000013e91e3af0] [c0080000072d61b8] kvm_arch_vcpu_ioctl_run+0x310/0x420 [kvm] [ 538.544539] [c0000013e91e3b80] [c0080000072c7450] kvm_vcpu_ioctl+0x298/0x778 [kvm] [ 538.544605] [c0000013e91e3ce0] [c0000000004b8c2c] sys_ioctl+0x1dc/0xc90 [ 538.544662] [c0000013e91e3dc0] [c00000000002f9a4] system_call_exception+0xe4/0x1c0 [ 538.544726] [c0000013e91e3e20] [c00000000000d140] system_call_common+0xf0/0x27c [ 538.544787] Instruction dump: [ 538.544821] f86d1098 60000000 60000000 48000099 e8ad0fe8 e8c500a0 e9264140 75290002 [ 538.544886] 7d1602a6 7cec42a6 40820008 7d0807b4 <7d164ba6> 7d083a14 f90d10a0 480104fd [ 538.544953] ---[ end trace 74423e2b948c2e0c ]--- This patch makes the KVM_PPC_ALLOCATE_HTAB ioctl fail when running in the nested hypervisor, causing QEMU to abort. Reported-by:Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Signed-off-by:
Greg Kurz <groug@kaod.org> Reviewed-by:
David Gibson <david@gibson.dropbear.id.au> Signed-off-by:
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Greg Kurz authored
ENOTSUPP is a linux only thingy, the value of which is unknown to userspace, not to be confused with ENOTSUP which linux maps to EOPNOTSUPP, as permitted by POSIX [1]: [EOPNOTSUPP] Operation not supported on socket. The type of socket (address family or protocol) does not support the requested operation. A conforming implementation may assign the same values for [EOPNOTSUPP] and [ENOTSUP]. Return -EOPNOTSUPP instead of -ENOTSUPP for the following ioctls: - KVM_GET_FPU for Book3s and BookE - KVM_SET_FPU for Book3s and BookE - KVM_GET_DIRTY_LOG for BookE This doesn't affect QEMU which doesn't call the KVM_GET_FPU and KVM_SET_FPU ioctls on POWER anyway since they are not supported, and _buggily_ ignores anything but -EPERM for KVM_GET_DIRTY_LOG. [1] https://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.htmlSigned-off-by:
Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by:
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