kernel/arch/arm64/kvm/hyp/entry.S, branch linux-6.2.y

KVM: arm64: Save/restore MTE registers

2021-06-22T13:08:05Z

Define the new system registers that MTE introduces and context switch them. The MTE feature is still hidden from the ID register as it isn't supported in a VM yet. Reviewed-by: Catalin Marinas Signed-off-by: Steven Price Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210621111716.37157-4-steven.price@arm.com

KVM: arm64: Don't use cbz/adr with external symbols

2021-03-09T08:48:24Z

allmodconfig + CONFIG_LTO_CLANG_THIN=y fails to build due to following linker errors: ld.lld: error: irqbypass.c:(function __guest_enter: .text+0x21CC): relocation R_AARCH64_CONDBR19 out of range: 2031220 is not in [-1048576, 1048575]; references hyp_panic >>> defined in vmlinux.o ld.lld: error: irqbypass.c:(function __guest_enter: .text+0x21E0): relocation R_AARCH64_ADR_PREL_LO21 out of range: 2031200 is not in [-1048576, 1048575]; references hyp_panic >>> defined in vmlinux.o This is because with LTO, the compiler ends up placing hyp_panic() more than 1MB away from __guest_enter(). Use an unconditional branch and adr_l instead to fix the issue. Link: https://github.com/ClangBuiltLinux/linux/issues/1317 Reported-by: Nathan Chancellor Suggested-by: Marc Zyngier Suggested-by: Ard Biesheuvel Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook Acked-by: Will Deacon Tested-by: Nathan Chancellor Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210305202124.3768527-1-samitolvanen@google.com

KVM: arm64: Avoid corrupting vCPU context register in guest exit

2021-03-06T09:18:40Z

Commit 7db21530479f ("KVM: arm64: Restore hyp when panicking in guest context") tracks the currently running vCPU, clearing the pointer to NULL on exit from a guest. Unfortunately, the use of 'set_loaded_vcpu' clobbers x1 to point at the kvm_hyp_ctxt instead of the vCPU context, causing the subsequent RAS code to go off into the weeds when it saves the DISR assuming that the CPU context is embedded in a struct vCPU. Leave x1 alone and use x3 as a temporary register instead when clearing the vCPU on the guest exit path. Cc: Marc Zyngier Cc: Andrew Scull Cc: Fixes: 7db21530479f ("KVM: arm64: Restore hyp when panicking in guest context") Suggested-by: Quentin Perret Signed-off-by: Will Deacon Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210226181211.14542-1-will@kernel.org Message-Id: <20210305185254.3730990-3-maz@kernel.org> Signed-off-by: Paolo Bonzini

Merge branch 'kvm-arm64/hyp-pcpu' into kvmarm-master/next

2020-09-30T13:05:35Z

Signed-off-by: Marc Zyngier

KVM: arm64: Share context save and restore macros

2020-09-15T17:39:03Z

To avoid duplicating the context save and restore macros, move them into a shareable header. Signed-off-by: Andrew Scull Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20200915104643.2543892-12-ascull@google.com

KVM: arm64: Restore hyp when panicking in guest context

2020-09-15T17:39:02Z

If the guest context is loaded when a panic is triggered, restore the hyp context so e.g. the shadow call stack works when hyp_panic() is called and SP_EL0 is valid when the host's panic() is called. Use the hyp context's __hyp_running_vcpu field to track when hyp transitions to and from the guest vcpu so the exception handlers know whether the context needs to be restored. Signed-off-by: Andrew Scull Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20200915104643.2543892-11-ascull@google.com

KVM: arm64: Update context references from host to hyp

2020-09-15T17:39:02Z

Hyp now has its own nominal context for saving and restoring its state when switching to and from a guest. Update the related comments and utilities to match the new name. Signed-off-by: Andrew Scull Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20200915104643.2543892-10-ascull@google.com

KVM: arm64: Introduce hyp context

2020-09-15T17:39:02Z

During __guest_enter, save and restore from a new hyp context rather than the host context. This is preparation for separation of the hyp and host context in nVHE. Signed-off-by: Andrew Scull Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20200915104643.2543892-9-ascull@google.com

KVM: arm64: Add kvm_extable for vaxorcism code

2020-08-28T14:23:42Z

KVM has a one instruction window where it will allow an SError exception to be consumed by the hypervisor without treating it as a hypervisor bug. This is used to consume asynchronous external abort that were caused by the guest. As we are about to add another location that survives unexpected exceptions, generalise this code to make it behave like the host's extable. KVM's version has to be mapped to EL2 to be accessible on nVHE systems. The SError vaxorcism code is a one instruction window, so has two entries in the extable. Because the KVM code is copied for VHE and nVHE, we end up with four entries, half of which correspond with code that isn't mapped. Signed-off-by: James Morse Reviewed-by: Marc Zyngier Signed-off-by: Catalin Marinas

KVM: arm64: Make struct kvm_regs userspace-only

2020-07-07T08:28:38Z

struct kvm_regs is used by userspace to indicate which register gets accessed by the {GET,SET}_ONE_REG API. But as we're about to refactor the layout of the in-kernel register structures, we need the kernel to move away from it. Let's make kvm_regs userspace only, and let the kernel map it to its own internal representation. Reviewed-by: James Morse Signed-off-by: Marc Zyngier