kernel.git/arch/x86/include/asm/mshyperv.h, branch linux-6.4.y

Merge tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2023-04-28T21:02:54Z

Pull objtool updates from Ingo Molnar: - Mark arch_cpu_idle_dead() __noreturn, make all architectures & drivers that did this inconsistently follow this new, common convention, and fix all the fallout that objtool can now detect statically - Fix/improve the ORC unwinder becoming unreliable due to UNWIND_HINT_EMPTY ambiguity, split it into UNWIND_HINT_END_OF_STACK and UNWIND_HINT_UNDEFINED to resolve it - Fix noinstr violations in the KCSAN code and the lkdtm/stackleak code - Generate ORC data for __pfx code - Add more __noreturn annotations to various kernel startup/shutdown and panic functions - Misc improvements & fixes * tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits) x86/hyperv: Mark hv_ghcb_terminate() as noreturn scsi: message: fusion: Mark mpt_halt_firmware() __noreturn x86/cpu: Mark {hlt,resume}_play_dead() __noreturn btrfs: Mark btrfs_assertfail() __noreturn objtool: Include weak functions in global_noreturns check cpu: Mark nmi_panic_self_stop() __noreturn cpu: Mark panic_smp_self_stop() __noreturn arm64/cpu: Mark cpu_park_loop() and friends __noreturn x86/head: Mark *_start_kernel() __noreturn init: Mark start_kernel() __noreturn init: Mark [arch_call_]rest_init() __noreturn objtool: Generate ORC data for __pfx code x86/linkage: Fix padding for typed functions objtool: Separate prefix code from stack validation code objtool: Remove superfluous dead_end_function() check objtool: Add symbol iteration helpers objtool: Add WARN_INSN() scripts/objdump-func: Support multiple functions context_tracking: Fix KCSAN noinstr violation objtool: Add stackleak instrumentation to uaccess safe list ...

x86/hyperv: VTL support for Hyper-V

2023-04-18T17:29:52Z

Virtual Trust Levels (VTL) helps enable Hyper-V Virtual Secure Mode (VSM) feature. VSM is a set of hypervisor capabilities and enlightenments offered to host and guest partitions which enable the creation and management of new security boundaries within operating system software. VSM achieves and maintains isolation through VTLs. Add early initialization for Virtual Trust Levels (VTL). This includes initializing the x86 platform for VTL and enabling boot support for secondary CPUs to start in targeted VTL context. For now, only enable the code for targeted VTL level as 2. When starting an AP at a VTL other than VTL0, the AP must start directly in 64-bit mode, bypassing the usual 16-bit -> 32-bit -> 64-bit mode transition sequence that occurs after waking up an AP with SIPI whose vector points to the 16-bit AP startup trampoline code. Signed-off-by: Saurabh Sengar Reviewed-by: Michael Kelley Reviewed-by: Stanislav Kinsburskii Link: https://lore.kernel.org/r/1681192532-15460-6-git-send-email-ssengar@linux.microsoft.com Signed-off-by: Wei Liu

x86/hyperv: Make hv_get_nmi_reason public

2023-04-18T17:29:52Z

Move hv_get_nmi_reason to .h file so it can be used in other modules as well. Signed-off-by: Saurabh Sengar Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/1681192532-15460-4-git-send-email-ssengar@linux.microsoft.com Signed-off-by: Wei Liu

x86/hyperv: Mark hv_ghcb_terminate() as noreturn

2023-04-14T15:31:28Z

Annotate the function prototype and definition as noreturn to prevent objtool warnings like: vmlinux.o: warning: objtool: hyperv_init+0x55c: unreachable instruction Also, as per Josh's suggestion, add it to the global_noreturns list. As a comparison, an objdump output without the annotation: [...] 1b63: mov $0x1,%esi 1b68: xor %edi,%edi 1b6a: callq ffffffff8102f680 1b6f: jmpq ffffffff82f217ec # unreachable 1b74: cmpq $0xffffffffffffffff,-0x702a24(%rip) [...] Now, after adding the __noreturn to the function prototype: [...] 17df: callq ffffffff8102f6d0 17e4: test %al,%al 17e6: je ffffffff82f21bb9 [...] 1bb9: mov $0x1,%esi 1bbe: xor %edi,%edi 1bc0: callq ffffffff8102f680 1bc5: nopw %cs:0x0(%rax,%rax,1) # end of function Reported-by: Arnd Bergmann Signed-off-by: Guilherme G. Piccoli Signed-off-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/32453a703dfcf0d007b473c9acbf70718222b74b.1681342859.git.jpoimboe@kernel.org

x86/hyperv: Change vTOM handling to use standard coco mechanisms

2023-03-27T07:31:43Z

Hyper-V guests on AMD SEV-SNP hardware have the option of using the "virtual Top Of Memory" (vTOM) feature specified by the SEV-SNP architecture. With vTOM, shared vs. private memory accesses are controlled by splitting the guest physical address space into two halves. vTOM is the dividing line where the uppermost bit of the physical address space is set; e.g., with 47 bits of guest physical address space, vTOM is 0x400000000000 (bit 46 is set). Guest physical memory is accessible at two parallel physical addresses -- one below vTOM and one above vTOM. Accesses below vTOM are private (encrypted) while accesses above vTOM are shared (decrypted). In this sense, vTOM is like the GPA.SHARED bit in Intel TDX. Support for Hyper-V guests using vTOM was added to the Linux kernel in two patch sets[1][2]. This support treats the vTOM bit as part of the physical address. For accessing shared (decrypted) memory, these patch sets create a second kernel virtual mapping that maps to physical addresses above vTOM. A better approach is to treat the vTOM bit as a protection flag, not as part of the physical address. This new approach is like the approach for the GPA.SHARED bit in Intel TDX. Rather than creating a second kernel virtual mapping, the existing mapping is updated using recently added coco mechanisms. When memory is changed between private and shared using set_memory_decrypted() and set_memory_encrypted(), the PTEs for the existing kernel mapping are changed to add or remove the vTOM bit in the guest physical address, just as with TDX. The hypercalls to change the memory status on the host side are made using the existing callback mechanism. Everything just works, with a minor tweak to map the IO-APIC to use private accesses. To accomplish the switch in approach, the following must be done: * Update Hyper-V initialization to set the cc_mask based on vTOM and do other coco initialization. * Update physical_mask so the vTOM bit is no longer treated as part of the physical address * Remove CC_VENDOR_HYPERV and merge the associated vTOM functionality under CC_VENDOR_AMD. Update cc_mkenc() and cc_mkdec() to set/clear the vTOM bit as a protection flag. * Code already exists to make hypercalls to inform Hyper-V about pages changing between shared and private. Update this code to run as a callback from __set_memory_enc_pgtable(). * Remove the Hyper-V special case from __set_memory_enc_dec() * Remove the Hyper-V specific call to swiotlb_update_mem_attributes() since mem_encrypt_init() will now do it. * Add a Hyper-V specific implementation of the is_private_mmio() callback that returns true for the IO-APIC and vTPM MMIO addresses [1] https://lore.kernel.org/all/20211025122116.264793-1-ltykernel@gmail.com/ [2] https://lore.kernel.org/all/20211213071407.314309-1-ltykernel@gmail.com/ [ bp: Touchups. ] Signed-off-by: Michael Kelley Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/1679838727-87310-7-git-send-email-mikelley@microsoft.com

x86/hyperv: Fix hv_get/set_register for nested bringup

2023-02-16T14:32:37Z

hv_get_nested_reg only translates SINT0, resulting in the wrong sint being registered by nested vmbus. Fix the issue with new utility function hv_is_sint_reg. While at it, improve clarity of hv_set_non_nested_register and hv_is_synic_reg. Signed-off-by: Nuno Das Neves Reviewed-by: Jinank Jain Link: https://lore.kernel.org/r/1675980172-6851-1-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu

x86/hyperv: Add an interface to do nested hypercalls

2023-01-17T13:37:19Z

According to TLFS, in order to communicate to L0 hypervisor there needs to be an additional bit set in the control register. This communication is required to perform privileged instructions which can only be performed by L0 hypervisor. An example of that could be setting up the VMBus infrastructure. Signed-off-by: Jinank Jain Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/24f9d46d5259a688113e6e5e69e21002647f4949.1672639707.git.jinankjain@linux.microsoft.com Signed-off-by: Wei Liu

Drivers: hv: Setup synic registers in case of nested root partition

2023-01-17T13:36:43Z

Child partitions are free to allocate SynIC message and event page but in case of root partition it must use the pages allocated by Microsoft Hypervisor (MSHV). Base address for these pages can be found using synthetic MSRs exposed by MSHV. There is a slight difference in those MSRs for nested vs non-nested root partition. Signed-off-by: Jinank Jain Reviewed-by: Nuno Das Neves Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/cb951fb1ad6814996fc54f4a255c5841a20a151f.1672639707.git.jinankjain@linux.microsoft.com Signed-off-by: Wei Liu

clocksource/drivers/hyper-v: Include asm/hyperv-tlfs.h not asm/mshyperv.h

2022-11-17T12:58:32Z

clocksource/hyperv_timer.h is included into the VDSO build. It includes asm/mshyperv.h which in turn includes the world and some more. This worked so far by chance, but any subtle change in the include chain results in a build breakage because VDSO builds are building user space libraries. Include asm/hyperv-tlfs.h instead which contains everything what the VDSO build needs except the hv_get_raw_timer() define. Move this define into a separate header file, which contains the prerequisites (msr.h) and is included by clocksource/hyperv_timer.h. Fixup drivers/hv/vmbus_drv.c which relies on the indirect include of asm/mshyperv.h. With that the VDSO build only pulls in the minimum requirements. Signed-off-by: Thomas Gleixner Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/87fsemtut0.ffs@tglx

x86/Hyper-V: Add SEV negotiate protocol support in Isolation VM

2022-06-15T18:27:40Z

Hyper-V Isolation VM current code uses sev_es_ghcb_hv_call() to read/write MSR via GHCB page and depends on the sev code. This may cause regression when sev code changes interface design. The latest SEV-ES code requires to negotiate GHCB version before reading/writing MSR via GHCB page and sev_es_ghcb_hv_call() doesn't work for Hyper-V Isolation VM. Add Hyper-V ghcb related implementation to decouple SEV and Hyper-V code. Negotiate GHCB version in the hyperv_init() and use the version to communicate with Hyper-V in the ghcb hv call function. Fixes: 2ea29c5abbc2 ("x86/sev: Save the negotiated GHCB version") Signed-off-by: Tianyu Lan Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20220614014553.1915929-1-ltykernel@gmail.com Signed-off-by: Wei Liu