diff options
author | Andrew Scull <ascull@google.com> | 2020-09-15 11:46:42 +0100 |
---|---|---|
committer | Marc Zyngier <maz@kernel.org> | 2020-09-15 18:39:04 +0100 |
commit | 04e4caa8d355d19fd7d26734bd2b9e3b563bb22a (patch) | |
tree | 1d34c6b73889f17c590e6870dda984c3e0cf7e06 | |
parent | 054698316d87a13e4c0dc8f5ecdd77b12e5eb676 (diff) |
KVM: arm64: nVHE: Migrate hyp-init to SMCCC
To complete the transition to SMCCC, the hyp initialization is given a
function ID. This looks neater than comparing the hyp stub function IDs
to the page table physical address.
Some care is taken to only clobber x0-3 before the host context is saved
as only those registers can be clobbered accoring to SMCCC. Fortunately,
only a few acrobatics are needed. The possible new tpidr_el2 is moved to
the argument in x2 so that it can be stashed in tpidr_el2 early to free
up a scratch register. The page table configuration then makes use of
x0-2.
Signed-off-by: Andrew Scull <ascull@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200915104643.2543892-19-ascull@google.com
-rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 5 | ||||
-rw-r--r-- | arch/arm64/kvm/Makefile | 2 | ||||
-rw-r--r-- | arch/arm64/kvm/arm.c | 5 | ||||
-rw-r--r-- | arch/arm64/kvm/hyp.S | 22 | ||||
-rw-r--r-- | arch/arm64/kvm/hyp/nvhe/hyp-init.S | 66 |
5 files changed, 43 insertions, 57 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 82c941cf8890..ef0325c42ca0 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -480,11 +480,6 @@ int kvm_test_age_hva(struct kvm *kvm, unsigned long hva); void kvm_arm_halt_guest(struct kvm *kvm); void kvm_arm_resume_guest(struct kvm *kvm); -u64 __kvm_call_hyp_init(phys_addr_t pgd_ptr, - unsigned long hyp_stack_ptr, - unsigned long vector_ptr, - unsigned long tpidr_el2); - #define kvm_call_hyp_nvhe(f, ...) \ ({ \ struct arm_smccc_res res; \ diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index 99977c1972cc..1504c81fbf5d 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -13,7 +13,7 @@ obj-$(CONFIG_KVM) += hyp/ kvm-y := $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o \ $(KVM)/vfio.o $(KVM)/irqchip.o \ arm.o mmu.o mmio.o psci.o perf.o hypercalls.o pvtime.o \ - inject_fault.o regmap.o va_layout.o hyp.o handle_exit.o \ + inject_fault.o regmap.o va_layout.o handle_exit.o \ guest.o debug.o reset.o sys_regs.o \ vgic-sys-reg-v3.o fpsimd.o pmu.o \ aarch32.o arch_timer.o \ diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 49aa08bd26de..c074d9824d54 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1264,6 +1264,7 @@ static void cpu_init_hyp_mode(void) unsigned long hyp_stack_ptr; unsigned long vector_ptr; unsigned long tpidr_el2; + struct arm_smccc_res res; /* Switch from the HYP stub to our own HYP init vector */ __hyp_set_vectors(kvm_get_idmap_vector()); @@ -1288,7 +1289,9 @@ static void cpu_init_hyp_mode(void) * cpus_have_const_cap() wrapper. */ BUG_ON(!system_capabilities_finalized()); - __kvm_call_hyp_init(pgd_ptr, hyp_stack_ptr, vector_ptr, tpidr_el2); + arm_smccc_1_1_hvc(KVM_HOST_SMCCC_FUNC(__kvm_hyp_init), + pgd_ptr, tpidr_el2, hyp_stack_ptr, vector_ptr, &res); + WARN_ON(res.a0 != SMCCC_RET_SUCCESS); /* * Disabling SSBD on a non-VHE system requires us to enable SSBS diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S deleted file mode 100644 index 12aa426f7559..000000000000 --- a/arch/arm64/kvm/hyp.S +++ /dev/null @@ -1,22 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-only */ -/* - * Copyright (C) 2012,2013 - ARM Ltd - * Author: Marc Zyngier <marc.zyngier@arm.com> - */ - -#include <linux/linkage.h> - -#include <asm/alternative.h> -#include <asm/assembler.h> -#include <asm/cpufeature.h> - -/* - * u64 __kvm_call_hyp_init(phys_addr_t pgd_ptr, - * unsigned long hyp_stack_ptr, - * unsigned long vector_ptr, - * unsigned long tpidr_el2); - */ -SYM_FUNC_START(__kvm_call_hyp_init) - hvc #0 - ret -SYM_FUNC_END(__kvm_call_hyp_init) diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S index abe885e26fe2..47224dc62c51 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-init.S +++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S @@ -4,11 +4,13 @@ * Author: Marc Zyngier <marc.zyngier@arm.com> */ +#include <linux/arm-smccc.h> #include <linux/linkage.h> #include <asm/alternative.h> #include <asm/assembler.h> #include <asm/kvm_arm.h> +#include <asm/kvm_asm.h> #include <asm/kvm_mmu.h> #include <asm/pgtable-hwdef.h> #include <asm/sysreg.h> @@ -44,27 +46,37 @@ __invalid: b . /* - * x0: HYP pgd - * x1: HYP stack - * x2: HYP vectors - * x3: per-CPU offset + * x0: SMCCC function ID + * x1: HYP pgd + * x2: per-CPU offset + * x3: HYP stack + * x4: HYP vectors */ __do_hyp_init: /* Check for a stub HVC call */ cmp x0, #HVC_STUB_HCALL_NR b.lo __kvm_handle_stub_hvc - phys_to_ttbr x4, x0 + /* Set tpidr_el2 for use by HYP to free a register */ + msr tpidr_el2, x2 + + mov x2, #KVM_HOST_SMCCC_FUNC(__kvm_hyp_init) + cmp x0, x2 + b.eq 1f + mov x0, #SMCCC_RET_NOT_SUPPORTED + eret + +1: phys_to_ttbr x0, x1 alternative_if ARM64_HAS_CNP - orr x4, x4, #TTBR_CNP_BIT + orr x0, x0, #TTBR_CNP_BIT alternative_else_nop_endif - msr ttbr0_el2, x4 + msr ttbr0_el2, x0 - mrs x4, tcr_el1 - mov_q x5, TCR_EL2_MASK - and x4, x4, x5 - mov x5, #TCR_EL2_RES1 - orr x4, x4, x5 + mrs x0, tcr_el1 + mov_q x1, TCR_EL2_MASK + and x0, x0, x1 + mov x1, #TCR_EL2_RES1 + orr x0, x0, x1 /* * The ID map may be configured to use an extended virtual address @@ -80,18 +92,18 @@ alternative_else_nop_endif * * So use the same T0SZ value we use for the ID map. */ - ldr_l x5, idmap_t0sz - bfi x4, x5, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH + ldr_l x1, idmap_t0sz + bfi x0, x1, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH /* * Set the PS bits in TCR_EL2. */ - tcr_compute_pa_size x4, #TCR_EL2_PS_SHIFT, x5, x6 + tcr_compute_pa_size x0, #TCR_EL2_PS_SHIFT, x1, x2 - msr tcr_el2, x4 + msr tcr_el2, x0 - mrs x4, mair_el1 - msr mair_el2, x4 + mrs x0, mair_el1 + msr mair_el2, x0 isb /* Invalidate the stale TLBs from Bootloader */ @@ -103,24 +115,22 @@ alternative_else_nop_endif * as well as the EE bit on BE. Drop the A flag since the compiler * is allowed to generate unaligned accesses. */ - mov_q x4, (SCTLR_EL2_RES1 | (SCTLR_ELx_FLAGS & ~SCTLR_ELx_A)) -CPU_BE( orr x4, x4, #SCTLR_ELx_EE) + mov_q x0, (SCTLR_EL2_RES1 | (SCTLR_ELx_FLAGS & ~SCTLR_ELx_A)) +CPU_BE( orr x0, x0, #SCTLR_ELx_EE) alternative_if ARM64_HAS_ADDRESS_AUTH - mov_q x5, (SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | \ + mov_q x1, (SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | \ SCTLR_ELx_ENDA | SCTLR_ELx_ENDB) - orr x4, x4, x5 + orr x0, x0, x1 alternative_else_nop_endif - msr sctlr_el2, x4 + msr sctlr_el2, x0 isb /* Set the stack and new vectors */ - mov sp, x1 - msr vbar_el2, x2 - - /* Set tpidr_el2 for use by HYP */ - msr tpidr_el2, x3 + mov sp, x3 + msr vbar_el2, x4 /* Hello, World! */ + mov x0, #SMCCC_RET_SUCCESS eret SYM_CODE_END(__kvm_hyp_init) |