KVM: arm64: Remove vector_ptr param of hyp-init

KVM precomputes the hyp VA of __kvm_hyp_host_vector, essentially a
constant (minus ASLR), before passing it to __kvm_hyp_init.
Now that we have alternatives for converting kimg VA to hyp VA, replace
this with computing the constant inside __kvm_hyp_init, thus removing
the need for an argument.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-10-dbrazdil@google.com

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index a542c422a036fa3c3b6441d5fc5df1efd2bf7a82..4698ea1fbb3778573209677780dd268cc0247d7d 100644 (file)
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -165,10 +165,8 @@ struct kvm_vcpu;
 struct kvm_s2_mmu;
 
 DECLARE_KVM_NVHE_SYM(__kvm_hyp_init);
-DECLARE_KVM_NVHE_SYM(__kvm_hyp_host_vector);
 DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
 #define __kvm_hyp_init         CHOOSE_NVHE_SYM(__kvm_hyp_init)
-#define __kvm_hyp_host_vector  CHOOSE_NVHE_SYM(__kvm_hyp_host_vector)
 #define __kvm_hyp_vector       CHOOSE_HYP_SYM(__kvm_hyp_vector)
 
 extern unsigned long kvm_arm_hyp_percpu_base[NR_CPUS];

diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 5633c5a27aad3547e9a504b412b4c1300b064458..ab6f96df20dfbffb8b9243cea96d435fd625eda0 100644 (file)
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -94,6 +94,30 @@ alternative_cb_end
        sub     \reg, \reg, \tmp
 .endm
 
+/*
+ * Convert a kernel image address to a hyp VA
+ * reg: kernel address to be converted in place
+ * tmp: temporary register
+ *
+ * The actual code generation takes place in kvm_get_kimage_voffset, and
+ * the instructions below are only there to reserve the space and
+ * perform the register allocation (kvm_update_kimg_phys_offset uses the
+ * specific registers encoded in the instructions).
+ */
+.macro kimg_hyp_va reg, tmp
+alternative_cb kvm_update_kimg_phys_offset
+       movz    \tmp, #0
+       movk    \tmp, #0, lsl #16
+       movk    \tmp, #0, lsl #32
+       movk    \tmp, #0, lsl #48
+alternative_cb_end
+
+       sub     \reg, \reg, \tmp
+       mov_q   \tmp, PAGE_OFFSET
+       orr     \reg, \reg, \tmp
+       kern_hyp_va \reg
+.endm
+
 #else
 
 #include <linux/pgtable.h>

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 745e1b4bcbe0534564be7854d98cd11ab4b650ae..1f86d7d0ecf2e0eef3238834df60fdba1a842582 100644 (file)
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1335,7 +1335,6 @@ static void cpu_init_hyp_mode(void)
 {
        phys_addr_t pgd_ptr;
        unsigned long hyp_stack_ptr;
-       unsigned long vector_ptr;
        unsigned long tpidr_el2;
        struct arm_smccc_res res;
 
@@ -1353,7 +1352,6 @@ static void cpu_init_hyp_mode(void)
        pgd_ptr = kvm_mmu_get_httbr();
        hyp_stack_ptr = __this_cpu_read(kvm_arm_hyp_stack_page) + PAGE_SIZE;
        hyp_stack_ptr = kern_hyp_va(hyp_stack_ptr);
-       vector_ptr = (unsigned long)kern_hyp_va(kvm_ksym_ref(__kvm_hyp_host_vector));
 
        /*
         * Call initialization code, and switch to the full blown HYP code.
@@ -1363,7 +1361,7 @@ static void cpu_init_hyp_mode(void)
         */
        BUG_ON(!system_capabilities_finalized());
        arm_smccc_1_1_hvc(KVM_HOST_SMCCC_FUNC(__kvm_hyp_init),
-                         pgd_ptr, tpidr_el2, hyp_stack_ptr, vector_ptr, &res);
+                         pgd_ptr, tpidr_el2, hyp_stack_ptr, &res);
        WARN_ON(res.a0 != SMCCC_RET_SUCCESS);
 
        /*

diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-init.S b/arch/arm64/kvm/hyp/nvhe/hyp-init.S
index b11a9d7db677db887f306d4f801a2bdb37cdcb1d..931a8c38f0854f9f1679f557860c917a35bb4e08 100644 (file)
--- a/arch/arm64/kvm/hyp/nvhe/hyp-init.S
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-init.S
@@ -50,7 +50,6 @@ __invalid:
         * x1: HYP pgd
         * x2: per-CPU offset
         * x3: HYP stack
-        * x4: HYP vectors
         */
 __do_hyp_init:
        /* Check for a stub HVC call */
@@ -134,9 +133,13 @@ alternative_else_nop_endif
        msr     sctlr_el2, x0
        isb
 
-       /* Set the stack and new vectors */
+       /* Set the stack */
        mov     sp, x3
-       msr     vbar_el2, x4
+
+       /* Set the host vector */
+       ldr     x0, =__kvm_hyp_host_vector
+       kimg_hyp_va x0, x1
+       msr     vbar_el2, x0
 
        /* Hello, World! */
        mov     x0, #SMCCC_RET_SUCCESS