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-rw-r--r--arch/arm64/include/asm/cpufeature.h3
-rw-r--r--arch/arm64/include/asm/kvm_arm.h2
-rw-r--r--arch/arm64/include/asm/kvm_host.h19
-rw-r--r--arch/arm64/include/asm/kvm_hyp.h23
-rw-r--r--arch/arm64/include/asm/kvm_mmu.h96
-rw-r--r--arch/arm64/include/asm/pgtable-hwdef.h1
-rw-r--r--arch/arm64/include/asm/pgtable-prot.h4
-rw-r--r--arch/arm64/include/asm/virt.h4
8 files changed, 95 insertions, 57 deletions
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 49dd1bd3ea50..7099f26e3702 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -36,8 +36,9 @@
#define ARM64_HAS_VIRT_HOST_EXTN 11
#define ARM64_WORKAROUND_CAVIUM_27456 12
#define ARM64_HAS_32BIT_EL0 13
+#define ARM64_HYP_OFFSET_LOW 14
-#define ARM64_NCAPS 14
+#define ARM64_NCAPS 15
#ifndef __ASSEMBLY__
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 2cdb6b551ac6..4b5c977af465 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -178,7 +178,7 @@
/* Hyp System Trap Register */
#define HSTR_EL2_T(x) (1 << x)
-/* Hyp Coproccessor Trap Register Shifts */
+/* Hyp Coprocessor Trap Register Shifts */
#define CPTR_EL2_TFP_SHIFT 10
/* Hyp Coprocessor Trap Register */
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 49095fc4b482..3eda975837d0 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -47,8 +47,7 @@
int __attribute_const__ kvm_target_cpu(void);
int kvm_reset_vcpu(struct kvm_vcpu *vcpu);
-int kvm_arch_dev_ioctl_check_extension(long ext);
-unsigned long kvm_hyp_reset_entry(void);
+int kvm_arch_dev_ioctl_check_extension(struct kvm *kvm, long ext);
void __extended_idmap_trampoline(phys_addr_t boot_pgd, phys_addr_t idmap_start);
struct kvm_arch {
@@ -348,8 +347,7 @@ int kvm_perf_teardown(void);
struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);
-static inline void __cpu_init_hyp_mode(phys_addr_t boot_pgd_ptr,
- phys_addr_t pgd_ptr,
+static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr,
unsigned long hyp_stack_ptr,
unsigned long vector_ptr)
{
@@ -357,19 +355,14 @@ static inline void __cpu_init_hyp_mode(phys_addr_t boot_pgd_ptr,
* Call initialization code, and switch to the full blown
* HYP code.
*/
- __kvm_call_hyp((void *)boot_pgd_ptr, pgd_ptr,
- hyp_stack_ptr, vector_ptr);
+ __kvm_call_hyp((void *)pgd_ptr, hyp_stack_ptr, vector_ptr);
}
-static inline void __cpu_reset_hyp_mode(phys_addr_t boot_pgd_ptr,
+void __kvm_hyp_teardown(void);
+static inline void __cpu_reset_hyp_mode(unsigned long vector_ptr,
phys_addr_t phys_idmap_start)
{
- /*
- * Call reset code, and switch back to stub hyp vectors.
- * Uses __kvm_call_hyp() to avoid kaslr's kvm_ksym_ref() translation.
- */
- __kvm_call_hyp((void *)kvm_hyp_reset_entry(),
- boot_pgd_ptr, phys_idmap_start);
+ kvm_call_hyp(__kvm_hyp_teardown, phys_idmap_start);
}
static inline void kvm_arch_hardware_unsetup(void) {}
diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index 44eaff70da6a..cff510574fae 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -25,29 +25,6 @@
#define __hyp_text __section(.hyp.text) notrace
-static inline unsigned long __kern_hyp_va(unsigned long v)
-{
- asm volatile(ALTERNATIVE("and %0, %0, %1",
- "nop",
- ARM64_HAS_VIRT_HOST_EXTN)
- : "+r" (v) : "i" (HYP_PAGE_OFFSET_MASK));
- return v;
-}
-
-#define kern_hyp_va(v) (typeof(v))(__kern_hyp_va((unsigned long)(v)))
-
-static inline unsigned long __hyp_kern_va(unsigned long v)
-{
- u64 offset = PAGE_OFFSET - HYP_PAGE_OFFSET;
- asm volatile(ALTERNATIVE("add %0, %0, %1",
- "nop",
- ARM64_HAS_VIRT_HOST_EXTN)
- : "+r" (v) : "r" (offset));
- return v;
-}
-
-#define hyp_kern_va(v) (typeof(v))(__hyp_kern_va((unsigned long)(v)))
-
#define read_sysreg_elx(r,nvh,vh) \
({ \
u64 reg; \
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index f05ac27d033e..b6bb83400cd8 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -29,21 +29,48 @@
*
* Instead, give the HYP mode its own VA region at a fixed offset from
* the kernel by just masking the top bits (which are all ones for a
- * kernel address).
+ * kernel address). We need to find out how many bits to mask.
*
- * ARMv8.1 (using VHE) does have a TTBR1_EL2, and doesn't use these
- * macros (the entire kernel runs at EL2).
+ * We want to build a set of page tables that cover both parts of the
+ * idmap (the trampoline page used to initialize EL2), and our normal
+ * runtime VA space, at the same time.
+ *
+ * Given that the kernel uses VA_BITS for its entire address space,
+ * and that half of that space (VA_BITS - 1) is used for the linear
+ * mapping, we can also limit the EL2 space to (VA_BITS - 1).
+ *
+ * The main question is "Within the VA_BITS space, does EL2 use the
+ * top or the bottom half of that space to shadow the kernel's linear
+ * mapping?". As we need to idmap the trampoline page, this is
+ * determined by the range in which this page lives.
+ *
+ * If the page is in the bottom half, we have to use the top half. If
+ * the page is in the top half, we have to use the bottom half:
+ *
+ * T = __virt_to_phys(__hyp_idmap_text_start)
+ * if (T & BIT(VA_BITS - 1))
+ * HYP_VA_MIN = 0 //idmap in upper half
+ * else
+ * HYP_VA_MIN = 1 << (VA_BITS - 1)
+ * HYP_VA_MAX = HYP_VA_MIN + (1 << (VA_BITS - 1)) - 1
+ *
+ * This of course assumes that the trampoline page exists within the
+ * VA_BITS range. If it doesn't, then it means we're in the odd case
+ * where the kernel idmap (as well as HYP) uses more levels than the
+ * kernel runtime page tables (as seen when the kernel is configured
+ * for 4k pages, 39bits VA, and yet memory lives just above that
+ * limit, forcing the idmap to use 4 levels of page tables while the
+ * kernel itself only uses 3). In this particular case, it doesn't
+ * matter which side of VA_BITS we use, as we're guaranteed not to
+ * conflict with anything.
+ *
+ * When using VHE, there are no separate hyp mappings and all KVM
+ * functionality is already mapped as part of the main kernel
+ * mappings, and none of this applies in that case.
*/
-#define HYP_PAGE_OFFSET_SHIFT VA_BITS
-#define HYP_PAGE_OFFSET_MASK ((UL(1) << HYP_PAGE_OFFSET_SHIFT) - 1)
-#define HYP_PAGE_OFFSET (PAGE_OFFSET & HYP_PAGE_OFFSET_MASK)
-/*
- * Our virtual mapping for the idmap-ed MMU-enable code. Must be
- * shared across all the page-tables. Conveniently, we use the last
- * possible page, where no kernel mapping will ever exist.
- */
-#define TRAMPOLINE_VA (HYP_PAGE_OFFSET_MASK & PAGE_MASK)
+#define HYP_PAGE_OFFSET_HIGH_MASK ((UL(1) << VA_BITS) - 1)
+#define HYP_PAGE_OFFSET_LOW_MASK ((UL(1) << (VA_BITS - 1)) - 1)
#ifdef __ASSEMBLY__
@@ -53,13 +80,33 @@
/*
* Convert a kernel VA into a HYP VA.
* reg: VA to be converted.
+ *
+ * This generates the following sequences:
+ * - High mask:
+ * and x0, x0, #HYP_PAGE_OFFSET_HIGH_MASK
+ * nop
+ * - Low mask:
+ * and x0, x0, #HYP_PAGE_OFFSET_HIGH_MASK
+ * and x0, x0, #HYP_PAGE_OFFSET_LOW_MASK
+ * - VHE:
+ * nop
+ * nop
+ *
+ * The "low mask" version works because the mask is a strict subset of
+ * the "high mask", hence performing the first mask for nothing.
+ * Should be completely invisible on any viable CPU.
*/
.macro kern_hyp_va reg
-alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
- and \reg, \reg, #HYP_PAGE_OFFSET_MASK
+alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
+ and \reg, \reg, #HYP_PAGE_OFFSET_HIGH_MASK
alternative_else
nop
alternative_endif
+alternative_if_not ARM64_HYP_OFFSET_LOW
+ nop
+alternative_else
+ and \reg, \reg, #HYP_PAGE_OFFSET_LOW_MASK
+alternative_endif
.endm
#else
@@ -70,7 +117,22 @@ alternative_endif
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
-#define KERN_TO_HYP(kva) ((unsigned long)kva - PAGE_OFFSET + HYP_PAGE_OFFSET)
+static inline unsigned long __kern_hyp_va(unsigned long v)
+{
+ asm volatile(ALTERNATIVE("and %0, %0, %1",
+ "nop",
+ ARM64_HAS_VIRT_HOST_EXTN)
+ : "+r" (v)
+ : "i" (HYP_PAGE_OFFSET_HIGH_MASK));
+ asm volatile(ALTERNATIVE("nop",
+ "and %0, %0, %1",
+ ARM64_HYP_OFFSET_LOW)
+ : "+r" (v)
+ : "i" (HYP_PAGE_OFFSET_LOW_MASK));
+ return v;
+}
+
+#define kern_hyp_va(v) (typeof(v))(__kern_hyp_va((unsigned long)(v)))
/*
* We currently only support a 40bit IPA.
@@ -81,9 +143,8 @@ alternative_endif
#include <asm/stage2_pgtable.h>
-int create_hyp_mappings(void *from, void *to);
+int create_hyp_mappings(void *from, void *to, pgprot_t prot);
int create_hyp_io_mappings(void *from, void *to, phys_addr_t);
-void free_boot_hyp_pgd(void);
void free_hyp_pgds(void);
void stage2_unmap_vm(struct kvm *kvm);
@@ -97,7 +158,6 @@ 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);
phys_addr_t kvm_get_idmap_start(void);
int kvm_mmu_init(void);
diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h
index 2813748e2f24..c3ae239db3ee 100644
--- a/arch/arm64/include/asm/pgtable-hwdef.h
+++ b/arch/arm64/include/asm/pgtable-hwdef.h
@@ -164,6 +164,7 @@
#define PTE_CONT (_AT(pteval_t, 1) << 52) /* Contiguous range */
#define PTE_PXN (_AT(pteval_t, 1) << 53) /* Privileged XN */
#define PTE_UXN (_AT(pteval_t, 1) << 54) /* User XN */
+#define PTE_HYP_XN (_AT(pteval_t, 1) << 54) /* HYP XN */
/*
* AttrIndx[2:0] encoding (mapping attributes defined in the MAIR* registers).
diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h
index 29fcb33ab401..39f5252673f7 100644
--- a/arch/arm64/include/asm/pgtable-prot.h
+++ b/arch/arm64/include/asm/pgtable-prot.h
@@ -55,7 +55,9 @@
#define PAGE_KERNEL_EXEC __pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_WRITE)
#define PAGE_KERNEL_EXEC_CONT __pgprot(_PAGE_DEFAULT | PTE_UXN | PTE_DIRTY | PTE_WRITE | PTE_CONT)
-#define PAGE_HYP __pgprot(_PAGE_DEFAULT | PTE_HYP)
+#define PAGE_HYP __pgprot(_PAGE_DEFAULT | PTE_HYP | PTE_HYP_XN)
+#define PAGE_HYP_EXEC __pgprot(_PAGE_DEFAULT | PTE_HYP | PTE_RDONLY)
+#define PAGE_HYP_RO __pgprot(_PAGE_DEFAULT | PTE_HYP | PTE_RDONLY | PTE_HYP_XN)
#define PAGE_HYP_DEVICE __pgprot(PROT_DEVICE_nGnRE | PTE_HYP)
#define PAGE_S2 __pgprot(PROT_DEFAULT | PTE_S2_MEMATTR(MT_S2_NORMAL) | PTE_S2_RDONLY)
diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h
index bbc6a8cf83f1..1788545f25bc 100644
--- a/arch/arm64/include/asm/virt.h
+++ b/arch/arm64/include/asm/virt.h
@@ -87,6 +87,10 @@ extern void verify_cpu_run_el(void);
static inline void verify_cpu_run_el(void) {}
#endif
+/* The section containing the hypervisor idmap text */
+extern char __hyp_idmap_text_start[];
+extern char __hyp_idmap_text_end[];
+
/* The section containing the hypervisor text */
extern char __hyp_text_start[];
extern char __hyp_text_end[];