[PATCH v2 5/6] KVM: arm/arm64: Stop using {pmd,pud,pgd}_populate
From: mark.rutland@arm.com (Mark Rutland)
Date: 2018-05-31 12:01:04
Also in:
kvm, kvmarm
On Wed, May 30, 2018 at 01:47:05PM +0100, Marc Zyngier wrote:
quoted hunk ↗ jump to hunk
The {pmd,pud,pgd}_populate accessors usage in the kernel have always been a bit weird in KVM. We don't have a struct mm to pass (and neither does the kernel most of the time, but still...), and the 32bit code has all kind of cache maintenance that doesn't make sense on ARMv7+ when MP extensions are mandatory (which is the case when the VEs are present). Let's bite the bullet and provide our own implementations. The only bit of architectural code left has to do with building the table entry itself (arm64 having up to 52bit PA, arm lacking PUD level). Signed-off-by: Marc Zyngier <redacted> --- arch/arm/include/asm/kvm_mmu.h | 4 ++++ arch/arm64/include/asm/kvm_mmu.h | 7 +++++++ virt/kvm/arm/mmu.c | 8 +++++--- 3 files changed, 16 insertions(+), 3 deletions(-)diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index 468ff945efa0..a94ef9833bd3 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h@@ -75,6 +75,10 @@ phys_addr_t kvm_get_idmap_vector(void); int kvm_mmu_init(void); void kvm_clear_hyp_idmap(void); +#define kvm_mk_pmd(ptep) __pmd(__pa(ptep) | PMD_TYPE_TABLE) +#define kvm_mk_pud(pmdp) __pud(__pa(pmdp) | PMD_TYPE_TABLE) +#define kvm_mk_pgd(pudp) ({ BUILD_BUG(); 0; })
I can't remember how the folding logic works for ARM is a pgd entry the entire pud table? Assuming so: Acked-by: Mark Rutland <mark.rutland@arm.com>
quoted hunk ↗ jump to hunk
+ static inline pte_t kvm_s2pte_mkwrite(pte_t pte) { pte_val(pte) |= L_PTE_S2_RDWR;diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 26c89b63f604..22c9f7cfdf93 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h@@ -170,6 +170,13 @@ phys_addr_t kvm_get_idmap_vector(void); int kvm_mmu_init(void); void kvm_clear_hyp_idmap(void); +#define kvm_mk_pmd(ptep) \ + __pmd(__phys_to_pmd_val(__pa(ptep) | PMD_TYPE_TABLE)) +#define kvm_mk_pud(pmdp) \ + __pud(__phys_to_pud_val(__pa(pmdp) | PMD_TYPE_TABLE)) +#define kvm_mk_pgd(pudp) \ + __pgd(__phys_to_pgd_val(__pa(pudp) | PUD_TYPE_TABLE)) + static inline pte_t kvm_s2pte_mkwrite(pte_t pte) { pte_val(pte) |= PTE_S2_RDWR;diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index c9ed239c0840..ad1980d2118a 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c@@ -191,17 +191,19 @@ static inline void kvm_set_pmd(pmd_t *pmdp, pmd_t new_pmd) static inline void kvm_pmd_populate(pmd_t *pmdp, pte_t *ptep) { - pmd_populate_kernel(NULL, pmdp, ptep); + kvm_set_pmd(pmdp, kvm_mk_pmd(ptep)); } static inline void kvm_pud_populate(pud_t *pudp, pmd_t *pmdp) { - pud_populate(NULL, pudp, pmdp); + WRITE_ONCE(*pudp, kvm_mk_pud(pmdp)); + dsb(ishst); } static inline void kvm_pgd_populate(pgd_t *pgdp, pud_t *pudp) { - pgd_populate(NULL, pgdp, pudp); + WRITE_ONCE(*pgdp, kvm_mk_pgd(pudp)); + dsb(ishst); } /*-- 2.17.1