diff options
| author | David Brazdil <dbrazdil@google.com> | 2020-12-02 18:41:17 +0000 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2020-12-04 10:08:35 +0000 |
| commit | cdf367192766ad11a03e8d5098556be43b8eb6b0 (patch) | |
| tree | ee070bb486a5f4afeeb21838655bfc1e298bd84a /arch/arm64/kvm/hyp/nvhe/hyp-init.S | |
| parent | 04e05f057a04275cb68c8053b29c5642ae0bad4f (diff) | |
KVM: arm64: Intercept host's CPU_ON SMCs
Add a handler of the CPU_ON PSCI call from host. When invoked, it looks
up the logical CPU ID corresponding to the provided MPIDR and populates
the state struct of the target CPU with the provided x0, pc. It then
calls CPU_ON itself, with an entry point in hyp that initializes EL2
state before returning ERET to the provided PC in EL1.
There is a simple atomic lock around the boot args struct. If it is
already locked, CPU_ON will return PENDING_ON error code.
Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-22-dbrazdil@google.com
Diffstat (limited to 'arch/arm64/kvm/hyp/nvhe/hyp-init.S')
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/hyp-init.S | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S index b0856b006bc0..d07e75f8242e 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-init.S +++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S @@ -9,6 +9,7 @@ #include <asm/alternative.h> #include <asm/assembler.h> +#include <asm/el2_setup.h> #include <asm/kvm_arm.h> #include <asm/kvm_asm.h> #include <asm/kvm_mmu.h> @@ -139,6 +140,53 @@ alternative_else_nop_endif ret SYM_CODE_END(___kvm_hyp_init) +/* + * PSCI CPU_ON entry point + * + * x0: struct kvm_nvhe_init_params PA + */ +SYM_CODE_START(kvm_hyp_cpu_entry) + mov x1, #1 // is_cpu_on = true + b __kvm_hyp_init_cpu +SYM_CODE_END(kvm_hyp_cpu_entry) + +/* + * Common code for CPU entry points. Initializes EL2 state and + * installs the hypervisor before handing over to a C handler. + * + * x0: struct kvm_nvhe_init_params PA + * x1: bool is_cpu_on + */ +SYM_CODE_START_LOCAL(__kvm_hyp_init_cpu) + mov x28, x0 // Stash arguments + mov x29, x1 + + /* Check that the core was booted in EL2. */ + mrs x0, CurrentEL + cmp x0, #CurrentEL_EL2 + b.eq 2f + + /* The core booted in EL1. KVM cannot be initialized on it. */ +1: wfe + wfi + b 1b + +2: msr SPsel, #1 // We want to use SP_EL{1,2} + + /* Initialize EL2 CPU state to sane values. */ + init_el2_state nvhe // Clobbers x0..x2 + + /* Enable MMU, set vectors and stack. */ + mov x0, x28 + bl ___kvm_hyp_init // Clobbers x0..x3 + + /* Leave idmap. */ + mov x0, x29 + ldr x1, =kvm_host_psci_cpu_entry + kimg_hyp_va x1, x2 + br x1 +SYM_CODE_END(__kvm_hyp_init_cpu) + SYM_CODE_START(__kvm_handle_stub_hvc) cmp x0, #HVC_SOFT_RESTART b.ne 1f |