arm64: kexec: configure EL2 vectors for kexec

If we have a EL2 mode without VHE, the EL2 vectors are needed in order
to switch to EL2 and jump to new world with hypervisor privileges.

In preparation to MMU enabled relocation, configure our EL2 table now.

Kexec uses #HVC_SOFT_RESTART to branch to the new world, so extend
el1_sync vector that is provided by trans_pgd_copy_el2_vectors() to
support this case.

Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-9-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 31 insertions, 0 deletions

diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
index e210b19592c6..59a4b4172b68 100644
--- a/arch/arm64/kernel/machine_kexec.c
+++ b/arch/arm64/kernel/machine_kexec.c
@@ -21,6 +21,7 @@
 #include <asm/mmu.h>
 #include <asm/mmu_context.h>
 #include <asm/page.h>
+#include <asm/trans_pgd.h>
 
 #include "cpu-reset.h"
 
@@ -43,7 +44,9 @@ static void _kexec_image_info(const char *func, int line,
 	pr_debug("    start:       %lx\n", kimage->start);
 	pr_debug("    head:        %lx\n", kimage->head);
 	pr_debug("    nr_segments: %lu\n", kimage->nr_segments);
+	pr_debug("    dtb_mem: %pa\n", &kimage->arch.dtb_mem);
 	pr_debug("    kern_reloc: %pa\n", &kimage->arch.kern_reloc);
+	pr_debug("    el2_vectors: %pa\n", &kimage->arch.el2_vectors);
 
 	for (i = 0; i < kimage->nr_segments; i++) {
 		pr_debug("      segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
@@ -143,9 +146,27 @@ static void kexec_segment_flush(const struct kimage *kimage)
 	}
 }
 
+/* Allocates pages for kexec page table */
+static void *kexec_page_alloc(void *arg)
+{
+	struct kimage *kimage = (struct kimage *)arg;
+	struct page *page = kimage_alloc_control_pages(kimage, 0);
+
+	if (!page)
+		return NULL;
+
+	memset(page_address(page), 0, PAGE_SIZE);
+
+	return page_address(page);
+}
+
 int machine_kexec_post_load(struct kimage *kimage)
 {
 	void *reloc_code = page_to_virt(kimage->control_code_page);
+	struct trans_pgd_info info = {
+		.trans_alloc_page	= kexec_page_alloc,
+		.trans_alloc_arg	= kimage,
+	};
 
 	/* If in place, relocation is not used, only flush next kernel */
 	if (kimage->head & IND_DONE) {
@@ -154,6 +175,14 @@ int machine_kexec_post_load(struct kimage *kimage)
 		return 0;
 	}
 
+	kimage->arch.el2_vectors = 0;
+	if (is_hyp_nvhe()) {
+		int rc = trans_pgd_copy_el2_vectors(&info,
+						    &kimage->arch.el2_vectors);
+		if (rc)
+			return rc;
+	}
+
 	memcpy(reloc_code, arm64_relocate_new_kernel,
 	       arm64_relocate_new_kernel_size);
 	kimage->arch.kern_reloc = __pa(reloc_code);
@@ -209,6 +238,8 @@ void machine_kexec(struct kimage *kimage)
 		restart(is_hyp_nvhe(), kimage->start, kimage->arch.dtb_mem,
 			0, 0);
 	} else {
+		if (is_hyp_nvhe())
+			__hyp_set_vectors(kimage->arch.el2_vectors);
 		cpu_soft_restart(kimage->arch.kern_reloc, virt_to_phys(kimage),
 				 0, 0);
 	}