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-rw-r--r--arch/arm/include/asm/kvm_host.h31
-rw-r--r--arch/arm/include/asm/kvm_mmu.h24
-rw-r--r--arch/arm/kvm/arm.c11
-rw-r--r--arch/arm/kvm/init.S78
-rw-r--r--arch/arm/kvm/mmu.c132
5 files changed, 197 insertions, 79 deletions
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 78813b8fad3..6c2a35da867 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -188,23 +188,30 @@ int kvm_arm_coproc_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *);
int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
int exception_index);
-static inline void __cpu_init_hyp_mode(unsigned long long pgd_ptr,
+static inline void __cpu_init_hyp_mode(unsigned long long boot_pgd_ptr,
+ unsigned long long pgd_ptr,
unsigned long hyp_stack_ptr,
unsigned long vector_ptr)
{
- unsigned long pgd_low, pgd_high;
-
- pgd_low = (pgd_ptr & ((1ULL << 32) - 1));
- pgd_high = (pgd_ptr >> 32ULL);
-
/*
- * Call initialization code, and switch to the full blown
- * HYP code. The init code doesn't need to preserve these registers as
- * r1-r3 and r12 are already callee save according to the AAPCS.
- * Note that we slightly misuse the prototype by casing the pgd_low to
- * a void *.
+ * Call initialization code, and switch to the full blown HYP
+ * code. The init code doesn't need to preserve these
+ * registers as r0-r3 are already callee saved according to
+ * the AAPCS.
+ * Note that we slightly misuse the prototype by casing the
+ * stack pointer to a void *.
+ *
+ * We don't have enough registers to perform the full init in
+ * one go. Install the boot PGD first, and then install the
+ * runtime PGD, stack pointer and vectors. The PGDs are always
+ * passed as the third argument, in order to be passed into
+ * r2-r3 to the init code (yes, this is compliant with the
+ * PCS!).
*/
- kvm_call_hyp((void *)pgd_low, pgd_high, hyp_stack_ptr, vector_ptr);
+
+ kvm_call_hyp(NULL, 0, boot_pgd_ptr);
+
+ kvm_call_hyp((void*)hyp_stack_ptr, vector_ptr, pgd_ptr);
}
int kvm_perf_init(void);
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index 92eb20d5794..24b767a8cdb 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -19,17 +19,29 @@
#ifndef __ARM_KVM_MMU_H__
#define __ARM_KVM_MMU_H__
-#include <asm/cacheflush.h>
-#include <asm/pgalloc.h>
+#include <asm/memory.h>
+#include <asm/page.h>
/*
* We directly use the kernel VA for the HYP, as we can directly share
* the mapping (HTTBR "covers" TTBR1).
*/
-#define HYP_PAGE_OFFSET_MASK (~0UL)
+#define HYP_PAGE_OFFSET_MASK UL(~0)
#define HYP_PAGE_OFFSET PAGE_OFFSET
#define KERN_TO_HYP(kva) (kva)
+/*
+ * Our virtual mapping for the boot-time MMU-enable code. Must be
+ * shared across all the page-tables. Conveniently, we use the vectors
+ * page, where no kernel data will ever be shared with HYP.
+ */
+#define TRAMPOLINE_VA UL(CONFIG_VECTORS_BASE)
+
+#ifndef __ASSEMBLY__
+
+#include <asm/cacheflush.h>
+#include <asm/pgalloc.h>
+
int create_hyp_mappings(void *from, void *to);
int create_hyp_io_mappings(void *from, void *to, phys_addr_t);
void free_hyp_pgds(void);
@@ -44,6 +56,8 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run);
void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu);
phys_addr_t kvm_mmu_get_httbr(void);
+phys_addr_t kvm_mmu_get_boot_httbr(void);
+phys_addr_t kvm_get_idmap_vector(void);
int kvm_mmu_init(void);
void kvm_clear_hyp_idmap(void);
@@ -113,4 +127,8 @@ static inline void coherent_icache_guest_page(struct kvm *kvm, gfn_t gfn)
}
}
+#define kvm_flush_dcache_to_poc(a,l) __cpuc_flush_dcache_area((a), (l))
+
+#endif /* !__ASSEMBLY__ */
+
#endif /* __ARM_KVM_MMU_H__ */
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 16f164a5db8..fc47bd721ab 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -787,20 +787,22 @@ long kvm_arch_vm_ioctl(struct file *filp,
static void cpu_init_hyp_mode(void *vector)
{
+ unsigned long long boot_pgd_ptr;
unsigned long long pgd_ptr;
unsigned long hyp_stack_ptr;
unsigned long stack_page;
unsigned long vector_ptr;
/* Switch from the HYP stub to our own HYP init vector */
- __hyp_set_vectors((unsigned long)vector);
+ __hyp_set_vectors(kvm_get_idmap_vector());
+ boot_pgd_ptr = (unsigned long long)kvm_mmu_get_boot_httbr();
pgd_ptr = (unsigned long long)kvm_mmu_get_httbr();
stack_page = __get_cpu_var(kvm_arm_hyp_stack_page);
hyp_stack_ptr = stack_page + PAGE_SIZE;
vector_ptr = (unsigned long)__kvm_hyp_vector;
- __cpu_init_hyp_mode(pgd_ptr, hyp_stack_ptr, vector_ptr);
+ __cpu_init_hyp_mode(boot_pgd_ptr, pgd_ptr, hyp_stack_ptr, vector_ptr);
}
/**
@@ -854,11 +856,6 @@ static int init_hyp_mode(void)
}
/*
- * Unmap the identity mapping
- */
- kvm_clear_hyp_idmap();
-
- /*
* Map the Hyp-code called directly from the host
*/
err = create_hyp_mappings(__kvm_hyp_code_start, __kvm_hyp_code_end);
diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S
index 9f37a79b880..f048338135f 100644
--- a/arch/arm/kvm/init.S
+++ b/arch/arm/kvm/init.S
@@ -21,13 +21,33 @@
#include <asm/asm-offsets.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_arm.h>
+#include <asm/kvm_mmu.h>
/********************************************************************
* Hypervisor initialization
* - should be called with:
- * r0,r1 = Hypervisor pgd pointer
- * r2 = top of Hyp stack (kernel VA)
- * r3 = pointer to hyp vectors
+ * r0 = top of Hyp stack (kernel VA)
+ * r1 = pointer to hyp vectors
+ * r2,r3 = Hypervisor pgd pointer
+ *
+ * The init scenario is:
+ * - We jump in HYP with four parameters: boot HYP pgd, runtime HYP pgd,
+ * runtime stack, runtime vectors
+ * - Enable the MMU with the boot pgd
+ * - Jump to a target into the trampoline page (remember, this is the same
+ * physical page!)
+ * - Now switch to the runtime pgd (same VA, and still the same physical
+ * page!)
+ * - Invalidate TLBs
+ * - Set stack and vectors
+ * - Profit! (or eret, if you only care about the code).
+ *
+ * As we only have four registers available to pass parameters (and we
+ * need six), we split the init in two phases:
+ * - Phase 1: r0 = 0, r1 = 0, r2,r3 contain the boot PGD.
+ * Provides the basic HYP init, and enable the MMU.
+ * - Phase 2: r0 = ToS, r1 = vectors, r2,r3 contain the runtime PGD.
+ * Switches to the runtime PGD, set stack and vectors.
*/
.text
@@ -47,22 +67,25 @@ __kvm_hyp_init:
W(b) .
__do_hyp_init:
+ cmp r0, #0 @ We have a SP?
+ bne phase2 @ Yes, second stage init
+
@ Set the HTTBR to point to the hypervisor PGD pointer passed
- mcrr p15, 4, r0, r1, c2
+ mcrr p15, 4, r2, r3, c2
@ Set the HTCR and VTCR to the same shareability and cacheability
@ settings as the non-secure TTBCR and with T0SZ == 0.
mrc p15, 4, r0, c2, c0, 2 @ HTCR
- ldr r12, =HTCR_MASK
- bic r0, r0, r12
+ ldr r2, =HTCR_MASK
+ bic r0, r0, r2
mrc p15, 0, r1, c2, c0, 2 @ TTBCR
and r1, r1, #(HTCR_MASK & ~TTBCR_T0SZ)
orr r0, r0, r1
mcr p15, 4, r0, c2, c0, 2 @ HTCR
mrc p15, 4, r1, c2, c1, 2 @ VTCR
- ldr r12, =VTCR_MASK
- bic r1, r1, r12
+ ldr r2, =VTCR_MASK
+ bic r1, r1, r2
bic r0, r0, #(~VTCR_HTCR_SH) @ clear non-reusable HTCR bits
orr r1, r0, r1
orr r1, r1, #(KVM_VTCR_SL0 | KVM_VTCR_T0SZ | KVM_VTCR_S)
@@ -85,24 +108,41 @@ __do_hyp_init:
@ - Memory alignment checks: enabled
@ - MMU: enabled (this code must be run from an identity mapping)
mrc p15, 4, r0, c1, c0, 0 @ HSCR
- ldr r12, =HSCTLR_MASK
- bic r0, r0, r12
+ ldr r2, =HSCTLR_MASK
+ bic r0, r0, r2
mrc p15, 0, r1, c1, c0, 0 @ SCTLR
- ldr r12, =(HSCTLR_EE | HSCTLR_FI | HSCTLR_I | HSCTLR_C)
- and r1, r1, r12
- ARM( ldr r12, =(HSCTLR_M | HSCTLR_A) )
- THUMB( ldr r12, =(HSCTLR_M | HSCTLR_A | HSCTLR_TE) )
- orr r1, r1, r12
+ ldr r2, =(HSCTLR_EE | HSCTLR_FI | HSCTLR_I | HSCTLR_C)
+ and r1, r1, r2
+ ARM( ldr r2, =(HSCTLR_M | HSCTLR_A) )
+ THUMB( ldr r2, =(HSCTLR_M | HSCTLR_A | HSCTLR_TE) )
+ orr r1, r1, r2
orr r0, r0, r1
isb
mcr p15, 4, r0, c1, c0, 0 @ HSCR
- isb
- @ Set stack pointer and return to the kernel
- mov sp, r2
+ @ End of init phase-1
+ eret
+
+phase2:
+ @ Set stack pointer
+ mov sp, r0
@ Set HVBAR to point to the HYP vectors
- mcr p15, 4, r3, c12, c0, 0 @ HVBAR
+ mcr p15, 4, r1, c12, c0, 0 @ HVBAR
+
+ @ Jump to the trampoline page
+ ldr r0, =TRAMPOLINE_VA
+ adr r1, target
+ bfi r0, r1, #0, #PAGE_SHIFT
+ mov pc, r0
+
+target: @ We're now in the trampoline code, switch page tables
+ mcrr p15, 4, r2, r3, c2
+ isb
+
+ @ Invalidate the old TLBs
+ mcr p15, 4, r0, c8, c7, 0 @ TLBIALLH
+ dsb
eret
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 7464824c17e..4646c17f571 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -32,9 +32,15 @@
extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[];
+static pgd_t *boot_hyp_pgd;
static pgd_t *hyp_pgd;
static DEFINE_MUTEX(kvm_hyp_pgd_mutex);
+static void *init_bounce_page;
+static unsigned long hyp_idmap_start;
+static unsigned long hyp_idmap_end;
+static phys_addr_t hyp_idmap_vector;
+
static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
{
kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa);
@@ -152,9 +158,12 @@ static void unmap_range(pgd_t *pgdp, unsigned long long start, u64 size)
/**
* free_hyp_pgds - free Hyp-mode page tables
*
- * Assumes hyp_pgd is a page table used strictly in Hyp-mode and therefore contains
- * either mappings in the kernel memory area (above PAGE_OFFSET), or
- * device mappings in the vmalloc range (from VMALLOC_START to VMALLOC_END).
+ * Assumes hyp_pgd is a page table used strictly in Hyp-mode and
+ * therefore contains either mappings in the kernel memory area (above
+ * PAGE_OFFSET), or device mappings in the vmalloc range (from
+ * VMALLOC_START to VMALLOC_END).
+ *
+ * boot_hyp_pgd should only map two pages for the init code.
*/
void free_hyp_pgds(void)
{
@@ -162,6 +171,12 @@ void free_hyp_pgds(void)
mutex_lock(&kvm_hyp_pgd_mutex);
+ if (boot_hyp_pgd) {
+ unmap_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);
+ unmap_range(boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);
+ kfree(boot_hyp_pgd);
+ }
+
if (hyp_pgd) {
for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE)
unmap_range(hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE);
@@ -170,6 +185,7 @@ void free_hyp_pgds(void)
kfree(hyp_pgd);
}
+ kfree(init_bounce_page);
mutex_unlock(&kvm_hyp_pgd_mutex);
}
@@ -185,6 +201,7 @@ static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start,
pte = pte_offset_kernel(pmd, addr);
kvm_set_pte(pte, pfn_pte(pfn, prot));
get_page(virt_to_page(pte));
+ kvm_flush_dcache_to_poc(pte, sizeof(*pte));
pfn++;
} while (addr += PAGE_SIZE, addr != end);
}
@@ -211,6 +228,7 @@ static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start,
}
pmd_populate_kernel(NULL, pmd, pte);
get_page(virt_to_page(pmd));
+ kvm_flush_dcache_to_poc(pmd, sizeof(*pmd));
}
next = pmd_addr_end(addr, end);
@@ -248,6 +266,7 @@ static int __create_hyp_mappings(pgd_t *pgdp,
}
pud_populate(NULL, pud, pmd);
get_page(virt_to_page(pud));
+ kvm_flush_dcache_to_poc(pud, sizeof(*pud));
}
next = pgd_addr_end(addr, end);
@@ -689,18 +708,64 @@ void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu)
phys_addr_t kvm_mmu_get_httbr(void)
{
- VM_BUG_ON(!virt_addr_valid(hyp_pgd));
return virt_to_phys(hyp_pgd);
}
+phys_addr_t kvm_mmu_get_boot_httbr(void)
+{
+ return virt_to_phys(boot_hyp_pgd);
+}
+
+phys_addr_t kvm_get_idmap_vector(void)
+{
+ return hyp_idmap_vector;
+}
+
int kvm_mmu_init(void)
{
- unsigned long hyp_idmap_start = virt_to_phys(__hyp_idmap_text_start);
- unsigned long hyp_idmap_end = virt_to_phys(__hyp_idmap_text_end);
int err;
+ hyp_idmap_start = virt_to_phys(__hyp_idmap_text_start);
+ hyp_idmap_end = virt_to_phys(__hyp_idmap_text_end);
+ hyp_idmap_vector = virt_to_phys(__kvm_hyp_init);
+
+ if ((hyp_idmap_start ^ hyp_idmap_end) & PAGE_MASK) {
+ /*
+ * Our init code is crossing a page boundary. Allocate
+ * a bounce page, copy the code over and use that.
+ */
+ size_t len = __hyp_idmap_text_end - __hyp_idmap_text_start;
+ phys_addr_t phys_base;
+
+ init_bounce_page = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!init_bounce_page) {
+ kvm_err("Couldn't allocate HYP init bounce page\n");
+ err = -ENOMEM;
+ goto out;
+ }
+
+ memcpy(init_bounce_page, __hyp_idmap_text_start, len);
+ /*
+ * Warning: the code we just copied to the bounce page
+ * must be flushed to the point of coherency.
+ * Otherwise, the data may be sitting in L2, and HYP
+ * mode won't be able to observe it as it runs with
+ * caches off at that point.
+ */
+ kvm_flush_dcache_to_poc(init_bounce_page, len);
+
+ phys_base = virt_to_phys(init_bounce_page);
+ hyp_idmap_vector += phys_base - hyp_idmap_start;
+ hyp_idmap_start = phys_base;
+ hyp_idmap_end = phys_base + len;
+
+ kvm_info("Using HYP init bounce page @%lx\n",
+ (unsigned long)phys_base);
+ }
+
hyp_pgd = kzalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL);
- if (!hyp_pgd) {
+ boot_hyp_pgd = kzalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL);
+ if (!hyp_pgd || !boot_hyp_pgd) {
kvm_err("Hyp mode PGD not allocated\n");
err = -ENOMEM;
goto out;
@@ -718,39 +783,30 @@ int kvm_mmu_init(void)
goto out;
}
+ /* Map the very same page at the trampoline VA */
+ err = __create_hyp_mappings(boot_hyp_pgd,
+ TRAMPOLINE_VA, TRAMPOLINE_VA + PAGE_SIZE,
+ __phys_to_pfn(hyp_idmap_start),
+ PAGE_HYP);
+ if (err) {
+ kvm_err("Failed to map trampoline @%lx into boot HYP pgd\n",
+ TRAMPOLINE_VA);
+ goto out;
+ }
+
+ /* Map the same page again into the runtime page tables */
+ err = __create_hyp_mappings(hyp_pgd,
+ TRAMPOLINE_VA, TRAMPOLINE_VA + PAGE_SIZE,
+ __phys_to_pfn(hyp_idmap_start),
+ PAGE_HYP);
+ if (err) {
+ kvm_err("Failed to map trampoline @%lx into runtime HYP pgd\n",
+ TRAMPOLINE_VA);
+ goto out;
+ }
+
return 0;
out:
free_hyp_pgds();
return err;
}
-
-/**
- * kvm_clear_idmap - remove all idmaps from the hyp pgd
- *
- * Free the underlying pmds for all pgds in range and clear the pgds (but
- * don't free them) afterwards.
- */
-void kvm_clear_hyp_idmap(void)
-{
- unsigned long addr, end;
- unsigned long next;
- pgd_t *pgd = hyp_pgd;
- pud_t *pud;
- pmd_t *pmd;
-
- addr = virt_to_phys(__hyp_idmap_text_start);
- end = virt_to_phys(__hyp_idmap_text_end);
-
- pgd += pgd_index(addr);
- do {
- next = pgd_addr_end(addr, end);
- if (pgd_none_or_clear_bad(pgd))
- continue;
- pud = pud_offset(pgd, addr);
- pmd = pmd_offset(pud, addr);
-
- pud_clear(pud);
- kvm_clean_pmd_entry(pmd);
- pmd_free(NULL, (pmd_t *)((unsigned long)pmd & PAGE_MASK));
- } while (pgd++, addr = next, addr < end);
-}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-10 23:45:06 +0000