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2020-09-25x86/sev-es: Use GHCB accessor for setting the MMIO scratch bufferTom Lendacky1-1/+1
Use ghcb_set_sw_scratch() to set the GHCB scratch field, which will also set the corresponding bit in the GHCB valid_bitmap field to denote that sw_scratch is actually valid. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Joerg Roedel <jroedel@suse.de> Link: https://lkml.kernel.org/r/ba84deabdf44a7a880454fb351d189c6ad79d4ba.1601041106.git.thomas.lendacky@amd.com
2020-09-10x86/sev-es: Check required CPU features for SEV-ESMartin Radev1-0/+3
Make sure the machine supports RDRAND, otherwise there is no trusted source of randomness in the system. To also check this in the pre-decompression stage, make has_cpuflag() not depend on CONFIG_RANDOMIZE_BASE anymore. Signed-off-by: Martin Radev <martin.b.radev@gmail.com> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/20200907131613.12703-73-joro@8bytes.org
2020-09-10x86/efi: Add GHCB mappings when SEV-ES is activeTom Lendacky1-0/+30
Calling down to EFI runtime services can result in the firmware performing VMGEXIT calls. The firmware is likely to use the GHCB of the OS (e.g., for setting EFI variables), so each GHCB in the system needs to be identity-mapped in the EFI page tables, as unencrypted, to avoid page faults. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> [ jroedel@suse.de: Moved GHCB mapping loop to sev-es.c ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lkml.kernel.org/r/20200907131613.12703-72-joro@8bytes.org
2020-09-09x86/sev-es: Handle NMI StateJoerg Roedel1-0/+18
When running under SEV-ES, the kernel has to tell the hypervisor when to open the NMI window again after an NMI was injected. This is done with an NMI-complete message to the hypervisor. Add code to the kernel's NMI handler to send this message right at the beginning of do_nmi(). This always allows nesting NMIs. [ bp: Mark __sev_es_nmi_complete() noinstr: vmlinux.o: warning: objtool: exc_nmi()+0x17: call to __sev_es_nmi_complete() leaves .noinstr.text section While at it, use __pa_nodebug() for the same reason due to CONFIG_DEBUG_VIRTUAL=y: vmlinux.o: warning: objtool: __sev_es_nmi_complete()+0xd9: call to __phys_addr() leaves .noinstr.text section ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-71-joro@8bytes.org
2020-09-09x86/sev-es: Support CPU offline/onlineJoerg Roedel1-0/+63
Add a play_dead handler when running under SEV-ES. This is needed because the hypervisor can't deliver an SIPI request to restart the AP. Instead, the kernel has to issue a VMGEXIT to halt the VCPU until the hypervisor wakes it up again. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-70-joro@8bytes.org
2020-09-09x86/realmode: Setup AP jump tableTom Lendacky1-0/+69
As part of the GHCB specification, the booting of APs under SEV-ES requires an AP jump table when transitioning from one layer of code to another (e.g. when going from UEFI to the OS). As a result, each layer that parks an AP must provide the physical address of an AP jump table to the next layer via the hypervisor. Upon booting of the kernel, read the AP jump table address from the hypervisor. Under SEV-ES, APs are started using the INIT-SIPI-SIPI sequence. Before issuing the first SIPI request for an AP, the start CS and IP is programmed into the AP jump table. Upon issuing the SIPI request, the AP will awaken and jump to that start CS:IP address. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> [ jroedel@suse.de: - Adapted to different code base - Moved AP table setup from SIPI sending path to real-mode setup code - Fix sparse warnings ] Co-developed-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-67-joro@8bytes.org
2020-09-09x86/paravirt: Allow hypervisor-specific VMMCALL handling under SEV-ESJoerg Roedel1-0/+12
Add two new paravirt callbacks to provide hypervisor-specific processor state in the GHCB and to copy state from the hypervisor back to the processor. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-63-joro@8bytes.org
2020-09-09x86/sev-es: Handle #DB EventsJoerg Roedel1-0/+17
Handle #VC exceptions caused by #DB exceptions in the guest. Those must be handled outside of instrumentation_begin()/end() so that the handler will not be raised recursively. Handle them by calling the kernel's debug exception handler. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-62-joro@8bytes.org
2020-09-09x86/sev-es: Handle #AC EventsJoerg Roedel1-0/+19
Implement a handler for #VC exceptions caused by #AC exceptions. The #AC exception is just forwarded to do_alignment_check() and not pushed down to the hypervisor, as requested by the SEV-ES GHCB Standardization Specification. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-61-joro@8bytes.org
2020-09-09x86/sev-es: Handle VMMCALL EventsTom Lendacky1-0/+23
Implement a handler for #VC exceptions caused by VMMCALL instructions. This is only a starting point, VMMCALL emulation under SEV-ES needs further hypervisor-specific changes to provide additional state. [ bp: Drop "this patch". ] Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> [ jroedel@suse.de: Adapt to #VC handling infrastructure ] Co-developed-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-60-joro@8bytes.org
2020-09-09x86/sev-es: Handle MWAIT/MWAITX EventsTom Lendacky1-0/+10
Implement a handler for #VC exceptions caused by MWAIT and MWAITX instructions. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> [ jroedel@suse.de: Adapt to #VC handling infrastructure ] Co-developed-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-59-joro@8bytes.org
2020-09-09x86/sev-es: Handle MONITOR/MONITORX EventsTom Lendacky1-0/+13
Implement a handler for #VC exceptions caused by MONITOR and MONITORX instructions. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> [ jroedel@suse.de: Adapt to #VC handling infrastructure ] Co-developed-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-58-joro@8bytes.org
2020-09-09x86/sev-es: Handle INVD EventsTom Lendacky1-0/+4
Implement a handler for #VC exceptions caused by INVD instructions. Since Linux should never use INVD, just mark it as unsupported. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> [ jroedel@suse.de: Adapt to #VC handling infrastructure ] Co-developed-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-57-joro@8bytes.org
2020-09-09x86/sev-es: Handle RDPMC EventsTom Lendacky1-0/+22
Implement a handler for #VC exceptions caused by RDPMC instructions. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> [ jroedel@suse.de: Adapt to #VC handling infrastructure ] Co-developed-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-56-joro@8bytes.org
2020-09-09x86/sev-es: Handle RDTSC(P) EventsTom Lendacky1-0/+4
Implement a handler for #VC exceptions caused by RDTSC and RDTSCP instructions. Also make it available in the pre-decompression stage because the KASLR code uses RDTSC/RDTSCP to gather entropy and some hypervisors intercept these instructions. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> [ jroedel@suse.de: - Adapt to #VC handling infrastructure - Make it available early ] Co-developed-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-55-joro@8bytes.org
2020-09-09x86/sev-es: Handle WBINVD EventsTom Lendacky1-0/+9
Implement a handler for #VC exceptions caused by WBINVD instructions. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> [ jroedel@suse.de: Adapt to #VC handling framework ] Co-developed-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-54-joro@8bytes.org
2020-09-09x86/sev-es: Handle DR7 read/write eventsTom Lendacky1-0/+85
Add code to handle #VC exceptions on DR7 register reads and writes. This is needed early because show_regs() reads DR7 to print it out. Under SEV-ES, there is currently no support for saving/restoring the DRx registers but software expects to be able to write to the DR7 register. For now, cache the value written to DR7 and return it on read attempts, but do not touch the real hardware DR7. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> [ jroedel@suse.de: - Adapt to #VC handling framework - Support early usage ] Co-developed-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-53-joro@8bytes.org
2020-09-09x86/sev-es: Handle MSR eventsTom Lendacky1-0/+28
Implement a handler for #VC exceptions caused by RDMSR/WRMSR instructions. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> [ jroedel@suse.de: Adapt to #VC handling infrastructure. ] Co-developed-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-52-joro@8bytes.org
2020-09-09x86/sev-es: Handle MMIO String InstructionsJoerg Roedel1-0/+77
Add handling for emulation of the MOVS instruction on MMIO regions, as done by the memcpy_toio() and memcpy_fromio() functions. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-51-joro@8bytes.org
2020-09-09x86/sev-es: Handle MMIO eventsTom Lendacky1-0/+222
Add a handler for #VC exceptions caused by MMIO intercepts. These intercepts come along as nested page faults on pages with reserved bits set. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> [ jroedel@suse.de: Adapt to VC handling framework ] Co-developed-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-50-joro@8bytes.org
2020-09-09x86/sev-es: Handle instruction fetches from user-spaceJoerg Roedel1-9/+22
When a #VC exception is triggered by user-space, the instruction decoder needs to read the instruction bytes from user addresses. Enhance vc_decode_insn() to safely fetch kernel and user instructions. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-49-joro@8bytes.org
2020-09-09x86/sev-es: Wire up existing #VC exit-code handlersJoerg Roedel1-0/+6
Re-use the handlers for CPUID- and IOIO-caused #VC exceptions in the early boot handler. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-48-joro@8bytes.org
2020-09-09x86/sev-es: Add a Runtime #VC Exception HandlerTom Lendacky1-4/+242
Add the handlers for #VC exceptions invoked at runtime. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-47-joro@8bytes.org
2020-09-09x86/sev-es: Adjust #VC IST Stack on entering NMI handlerJoerg Roedel1-0/+53
When an NMI hits in the #VC handler entry code before it has switched to another stack, any subsequent #VC exception in the NMI code-path will overwrite the interrupted #VC handler's stack. Make sure this doesn't happen by explicitly adjusting the #VC IST entry in the NMI handler for the time it can cause #VC exceptions. [ bp: Touchups, spelling fixes. ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-44-joro@8bytes.org
2020-09-09x86/sev-es: Allocate and map an IST stack for #VC handlerJoerg Roedel1-0/+33
Allocate and map an IST stack and an additional fall-back stack for the #VC handler. The memory for the stacks is allocated only when SEV-ES is active. The #VC handler needs to use an IST stack because a #VC exception can be raised from kernel space with unsafe stack, e.g. in the SYSCALL entry path. Since the #VC exception can be nested, the #VC handler switches back to the interrupted stack when entered from kernel space. If switching back is not possible, the fall-back stack is used. Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-43-joro@8bytes.org
2020-09-09x86/sev-es: Setup per-CPU GHCBs for the runtime handlerTom Lendacky1-1/+55
The runtime handler needs one GHCB per-CPU. Set them up and map them unencrypted. [ bp: Touchups and simplification. ] Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-42-joro@8bytes.org
2020-09-09x86/sev-es: Setup GHCB-based boot #VC handlerJoerg Roedel1-0/+116
Add the infrastructure to handle #VC exceptions when the kernel runs on virtual addresses and has mapped a GHCB. This handler will be used until the runtime #VC handler takes over. Since the handler runs very early, disable instrumentation for sev-es.c. [ bp: Make vc_ghcb_invalidate() __always_inline so that it can be inlined in noinstr functions like __sev_es_nmi_complete(). ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200908123816.GB3764@8bytes.org
2020-09-09x86/sev-es: Compile early handler code into kernel imageJoerg Roedel1-0/+163
Setup sev-es.c and include the code from the pre-decompression stage to also build it into the image of the running kernel. Temporarily add __maybe_unused annotations to avoid build warnings until the functions get used. [ bp: Use the non-tracing rd/wrmsr variants because: vmlinux.o: warning: objtool: __sev_es_nmi_complete()+0x11f: \ call to do_trace_write_msr() leaves .noinstr.text section as __sev_es_nmi_complete() is noinstr due to being called from the NMI handler exc_nmi(). ] Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20200907131613.12703-39-joro@8bytes.org
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