From: Vladimir Murzin <vladimir.mur...@arm.com>
The ARMv8.1 architecture extension allows to choose between 8-bit and
16-bit of VMID, so use this capability for KVM.
Reviewed-by: Christoffer Dall <christoffer.d...@linaro.org>
Signed-off-by: Vladimir Murzin <vladimir.mur...@arm.com>
Signed-off-by: Marc Zyngier <marc.zyng...@arm.com>
---
arch/arm/include/asm/kvm_arm.h | 2 +-
arch/arm/include/asm/kvm_mmu.h | 5 +++++
arch/arm/kvm/arm.c | 10 ++++++++--
arch/arm64/include/asm/kvm_arm.h | 3 ++-
arch/arm64/include/asm/kvm_mmu.h | 8 ++++++++
arch/arm64/kvm/hyp-init.S | 9 +++++++++
6 files changed, 33 insertions(+), 4 deletions(-)
diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h
index 01d4d7a..e22089f 100644
--- a/arch/arm/include/asm/kvm_arm.h
+++ b/arch/arm/include/asm/kvm_arm.h
@@ -164,7 +164,7 @@
#define VTTBR_BADDR_SHIFT (VTTBR_X - 1)
#define VTTBR_BADDR_MASK (((_AC(1, ULL) << (40 - VTTBR_X)) - 1) <<
VTTBR_BADDR_SHIFT)
#define VTTBR_VMID_SHIFT _AC(48, ULL)
-#define VTTBR_VMID_MASK (_AC(0xff, ULL) << VTTBR_VMID_SHIFT)
+#define VTTBR_VMID_MASK(size) (_AT(u64, (1 << size) - 1) << VTTBR_VMID_SHIFT)
/* Hyp Syndrome Register (HSR) bits */
#define HSR_EC_SHIFT (26)
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index 405aa18..9203c21 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -279,6 +279,11 @@ static inline void __kvm_extend_hypmap(pgd_t *boot_hyp_pgd,
pgd_t *merged_hyp_pgd,
unsigned long hyp_idmap_start) { }
+static inline unsigned int kvm_get_vmid_bits(void)
+{
+ return 8;
+}
+
#endif /* !__ASSEMBLY__ */
#endif /* __ARM_KVM_MMU_H__ */
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 6e35d1d..f6bcc2e 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -59,7 +59,8 @@ static DEFINE_PER_CPU(struct kvm_vcpu *,
kvm_arm_running_vcpu);
/* The VMID used in the VTTBR */
static atomic64_t kvm_vmid_gen = ATOMIC64_INIT(1);
-static u8 kvm_next_vmid;
+static u32 kvm_next_vmid;
+static unsigned int kvm_vmid_bits __read_mostly;
static DEFINE_SPINLOCK(kvm_vmid_lock);
static void kvm_arm_set_running_vcpu(struct kvm_vcpu *vcpu)
@@ -434,11 +435,12 @@ static void update_vttbr(struct kvm *kvm)
kvm->arch.vmid_gen = atomic64_read(&kvm_vmid_gen);
kvm->arch.vmid = kvm_next_vmid;
kvm_next_vmid++;
+ kvm_next_vmid &= (1 << kvm_vmid_bits) - 1;
/* update vttbr to be used with the new vmid */
pgd_phys = virt_to_phys(kvm_get_hwpgd(kvm));
BUG_ON(pgd_phys & ~VTTBR_BADDR_MASK);
- vmid = ((u64)(kvm->arch.vmid) << VTTBR_VMID_SHIFT) & VTTBR_VMID_MASK;
+ vmid = ((u64)(kvm->arch.vmid) << VTTBR_VMID_SHIFT) &
VTTBR_VMID_MASK(kvm_vmid_bits);
kvm->arch.vttbr = pgd_phys | vmid;
spin_unlock(&kvm_vmid_lock);
@@ -1135,6 +1137,10 @@ static int init_hyp_mode(void)
kvm_perf_init();
+ /* set size of VMID supported by CPU */
+ kvm_vmid_bits = kvm_get_vmid_bits();
+ kvm_info("%d-bit VMID\n", kvm_vmid_bits);
+
kvm_info("Hyp mode initialized successfully\n");
return 0;
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 5e6857b..738a95f 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -125,6 +125,7 @@
#define VTCR_EL2_SL0_LVL1 (1 << 6)
#define VTCR_EL2_T0SZ_MASK 0x3f
#define VTCR_EL2_T0SZ_40B 24
+#define VTCR_EL2_VS 19
/*
* We configure the Stage-2 page tables to always restrict the IPA space to be
@@ -169,7 +170,7 @@
#define VTTBR_BADDR_SHIFT (VTTBR_X - 1)
#define VTTBR_BADDR_MASK (((UL(1) << (PHYS_MASK_SHIFT - VTTBR_X)) - 1) <<
VTTBR_BADDR_SHIFT)
#define VTTBR_VMID_SHIFT (UL(48))
-#define VTTBR_VMID_MASK (UL(0xFF) << VTTBR_VMID_SHIFT)
+#define VTTBR_VMID_MASK(size) (_AT(u64, (1 << size) - 1) << VTTBR_VMID_SHIFT)
/* Hyp System Trap Register */
#define HSTR_EL2_T(x) (1 << x)
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 54cba80..0bf8b43 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -20,6 +20,7 @@
#include <asm/page.h>
#include <asm/memory.h>
+#include <asm/cpufeature.h>
/*
* As we only have the TTBR0_EL2 register, we cannot express
@@ -301,5 +302,12 @@ static inline void __kvm_extend_hypmap(pgd_t *boot_hyp_pgd,
merged_hyp_pgd[idmap_idx] = __pgd(__pa(boot_hyp_pgd) | PMD_TYPE_TABLE);
}
+static inline unsigned int kvm_get_vmid_bits(void)
+{
+ int reg = read_system_reg(SYS_ID_AA64MMFR1_EL1);
+
+ return (cpuid_feature_extract_field(reg, ID_AA64MMFR1_VMIDBITS_SHIFT)
== 2) ? 16 : 8;
+}
+
#endif /* __ASSEMBLY__ */
#endif /* __ARM64_KVM_MMU_H__ */
diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S
index 178ba22..3e568dc 100644
--- a/arch/arm64/kvm/hyp-init.S
+++ b/arch/arm64/kvm/hyp-init.S
@@ -94,6 +94,15 @@ __do_hyp_init:
*/
mrs x5, ID_AA64MMFR0_EL1
bfi x4, x5, #16, #3
+ /*
+ * Read the VMIDBits bits from ID_AA64MMFR1_EL1 and set the VS bit in
+ * VTCR_EL2.
+ */
+ mrs x5, ID_AA64MMFR1_EL1
+ ubfx x5, x5, #5, #1
+ lsl x5, x5, #VTCR_EL2_VS
+ orr x4, x4, x5
+
msr vtcr_el2, x4
mrs x4, mair_el1
--
2.1.4
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