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ARM: KVM: move to a KVM provided HYP idmap
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After the HYP page table rework, it is pretty easy to let the KVM
code provide its own idmap, rather than expecting the kernel to
provide it. It takes actually less code to do so.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
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Marc Zyngier authored and Christoffer Dall committed Apr 29, 2013
1 parent 3562c76 commit 2fb4105
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Showing 4 changed files with 24 additions and 34 deletions.
1 change: 0 additions & 1 deletion arch/arm/include/asm/idmap.h
Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,6 @@
#define __idmap __section(.idmap.text) noinline notrace

extern pgd_t *idmap_pgd;
extern pgd_t *hyp_pgd;

void setup_mm_for_reboot(void);

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1 change: 0 additions & 1 deletion arch/arm/include/asm/kvm_mmu.h
Original file line number Diff line number Diff line change
Expand Up @@ -21,7 +21,6 @@

#include <asm/cacheflush.h>
#include <asm/pgalloc.h>
#include <asm/idmap.h>

/*
* We directly use the kernel VA for the HYP, as we can directly share
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24 changes: 23 additions & 1 deletion arch/arm/kvm/mmu.c
Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,7 @@

extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[];

static pgd_t *hyp_pgd;
static DEFINE_MUTEX(kvm_hyp_pgd_mutex);

static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
Expand Down Expand Up @@ -715,12 +716,33 @@ phys_addr_t kvm_mmu_get_httbr(void)

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_pgd = kzalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL);
if (!hyp_pgd) {
kvm_err("Hyp mode PGD not allocated\n");
return -ENOMEM;
err = -ENOMEM;
goto out;
}

/* Create the idmap in the boot page tables */
err = __create_hyp_mappings(boot_hyp_pgd,
hyp_idmap_start, hyp_idmap_end,
__phys_to_pfn(hyp_idmap_start),
PAGE_HYP);

if (err) {
kvm_err("Failed to idmap %lx-%lx\n",
hyp_idmap_start, hyp_idmap_end);
goto out;
}

return 0;
out:
kfree(hyp_pgd);
return err;
}

/**
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32 changes: 1 addition & 31 deletions arch/arm/mm/idmap.c
Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,6 @@
#include <asm/pgtable.h>
#include <asm/sections.h>
#include <asm/system_info.h>
#include <asm/virt.h>

pgd_t *idmap_pgd;

Expand Down Expand Up @@ -83,37 +82,10 @@ static void identity_mapping_add(pgd_t *pgd, const char *text_start,
} while (pgd++, addr = next, addr != end);
}

#if defined(CONFIG_ARM_VIRT_EXT) && defined(CONFIG_ARM_LPAE)
pgd_t *hyp_pgd;

extern char __hyp_idmap_text_start[], __hyp_idmap_text_end[];

static int __init init_static_idmap_hyp(void)
{
hyp_pgd = kzalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL);
if (!hyp_pgd)
return -ENOMEM;

pr_info("Setting up static HYP identity map for 0x%p - 0x%p\n",
__hyp_idmap_text_start, __hyp_idmap_text_end);
identity_mapping_add(hyp_pgd, __hyp_idmap_text_start,
__hyp_idmap_text_end, PMD_SECT_AP1);

return 0;
}
#else
static int __init init_static_idmap_hyp(void)
{
return 0;
}
#endif

extern char __idmap_text_start[], __idmap_text_end[];

static int __init init_static_idmap(void)
{
int ret;

idmap_pgd = pgd_alloc(&init_mm);
if (!idmap_pgd)
return -ENOMEM;
Expand All @@ -123,12 +95,10 @@ static int __init init_static_idmap(void)
identity_mapping_add(idmap_pgd, __idmap_text_start,
__idmap_text_end, 0);

ret = init_static_idmap_hyp();

/* Flush L1 for the hardware to see this page table content */
flush_cache_louis();

return ret;
return 0;
}
early_initcall(init_static_idmap);

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