kernel.git/arch/x86/kernel/idt.c, branch linux-5.12.y

Merge tag 'x86_seves_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-10-14T17:21:34Z

Pull x86 SEV-ES support from Borislav Petkov: "SEV-ES enhances the current guest memory encryption support called SEV by also encrypting the guest register state, making the registers inaccessible to the hypervisor by en-/decrypting them on world switches. Thus, it adds additional protection to Linux guests against exfiltration, control flow and rollback attacks. With SEV-ES, the guest is in full control of what registers the hypervisor can access. This is provided by a guest-host exchange mechanism based on a new exception vector called VMM Communication Exception (#VC), a new instruction called VMGEXIT and a shared Guest-Host Communication Block which is a decrypted page shared between the guest and the hypervisor. Intercepts to the hypervisor become #VC exceptions in an SEV-ES guest so in order for that exception mechanism to work, the early x86 init code needed to be made able to handle exceptions, which, in itself, brings a bunch of very nice cleanups and improvements to the early boot code like an early page fault handler, allowing for on-demand building of the identity mapping. With that, !KASLR configurations do not use the EFI page table anymore but switch to a kernel-controlled one. The main part of this series adds the support for that new exchange mechanism. The goal has been to keep this as much as possibly separate from the core x86 code by concentrating the machinery in two SEV-ES-specific files: arch/x86/kernel/sev-es-shared.c arch/x86/kernel/sev-es.c Other interaction with core x86 code has been kept at minimum and behind static keys to minimize the performance impact on !SEV-ES setups. Work by Joerg Roedel and Thomas Lendacky and others" * tag 'x86_seves_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (73 commits) x86/sev-es: Use GHCB accessor for setting the MMIO scratch buffer x86/sev-es: Check required CPU features for SEV-ES x86/efi: Add GHCB mappings when SEV-ES is active x86/sev-es: Handle NMI State x86/sev-es: Support CPU offline/online x86/head/64: Don't call verify_cpu() on starting APs x86/smpboot: Load TSS and getcpu GDT entry before loading IDT x86/realmode: Setup AP jump table x86/realmode: Add SEV-ES specific trampoline entry point x86/vmware: Add VMware-specific handling for VMMCALL under SEV-ES x86/kvm: Add KVM-specific VMMCALL handling under SEV-ES x86/paravirt: Allow hypervisor-specific VMMCALL handling under SEV-ES x86/sev-es: Handle #DB Events x86/sev-es: Handle #AC Events x86/sev-es: Handle VMMCALL Events x86/sev-es: Handle MWAIT/MWAITX Events x86/sev-es: Handle MONITOR/MONITORX Events x86/sev-es: Handle INVD Events x86/sev-es: Handle RDPMC Events x86/sev-es: Handle RDTSC(P) Events ...

x86/platform/uv: Remove UV BAU TLB Shootdown Handler

2020-10-07T06:45:39Z

The Broadcast Assist Unit (BAU) TLB shootdown handler is being rewritten to become the UV BAU APIC driver. It is designed to speed up sending IPIs to selective CPUs within the system. Remove the current TLB shutdown handler (tlb_uv.c) file and a couple of kernel hooks in the interim. Signed-off-by: Mike Travis Signed-off-by: Borislav Petkov Reviewed-by: Dimitri Sivanich Link: https://lkml.kernel.org/r/20201005203929.148656-2-mike.travis@hpe.com

x86/sev-es: Add a Runtime #VC Exception Handler

2020-09-09T09:33:19Z

Add the handlers for #VC exceptions invoked at runtime. Signed-off-by: Tom Lendacky Signed-off-by: Joerg Roedel Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20200907131613.12703-47-joro@8bytes.org

x86/idt: Make IDT init functions static inlines

2020-09-07T20:44:43Z

Move these two functions from kernel/idt.c to include/asm/desc.h: * init_idt_data() * idt_init_desc() These functions are needed to setup IDT entries very early and need to be called from head64.c. To be usable this early, these functions need to be compiled without instrumentation and the stack-protector feature. These features need to be kept enabled for kernel/idt.c, so head64.c must use its own versions. [ bp: Take Kees' suggested patch title and add his Rev-by. ] Signed-off-by: Joerg Roedel Signed-off-by: Borislav Petkov Reviewed-by: Kees Cook Link: https://lkml.kernel.org/r/20200907131613.12703-35-joro@8bytes.org

x86/idt: Split idt_data setup out of set_intr_gate()

2020-09-07T19:30:38Z

The code to setup idt_data is needed for early exception handling, but set_intr_gate() can't be used that early because it has pv-ops in its code path which don't work that early. Split out the idt_data initialization part from set_intr_gate() so that it can be used separately. Signed-off-by: Joerg Roedel Signed-off-by: Borislav Petkov Reviewed-by: Kees Cook Link: https://lkml.kernel.org/r/20200907131613.12703-29-joro@8bytes.org

x86/idt: Make idt_descr static

2020-06-20T09:47:35Z

Commit 3e77abda65b1 ("x86/idt: Consolidate idt functionality") states that idt_descr could be made static, but it did not actually make the change. Make it static now. Fixes: 3e77abda65b1 ("x86/idt: Consolidate idt functionality") Signed-off-by: Jason Andryuk Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20200619205103.30873-1-jandryuk@gmail.com

x86/idt: Consolidate idt functionality

2020-06-11T13:15:26Z

- Move load_current_idt() out of line and replace the hideous comment with a lockdep assert. This allows to make idt_table and idt_descr static. - Mark idt_table read only after the IDT initialization is complete. - Shuffle code around to consolidate the #ifdef sections into one. - Adapt the F00F bug code. Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200528145523.084915381@linutronix.de

x86/idt: Cleanup trap_init()

2020-06-11T13:15:26Z

No point in having all the IDT cruft in trap_init(). Move it into the IDT code and fixup the comments. Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200528145522.992376498@linutronix.de

x86/idt: Use proper constants for table size

2020-06-11T13:15:25Z

Use the actual struct size to calculate the IDT table size instead of hardcoded values. Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200528145522.898591501@linutronix.de

x86/idt: Add comments about early #PF handling

2020-06-11T13:15:25Z

The difference between 32 and 64 bit vs. early #PF handling is not documented. Replace the FIXME at idt_setup_early_pf() with proper comments. Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200528145522.807135882@linutronix.de