KVM: ARM: Hypervisor initialization

Sets up KVM code to handle all exceptions taken to Hyp mode.

When the kernel is booted in Hyp mode, calling an hvc instruction with r0
pointing to the new vectors, the HVBAR is changed to the the vector pointers.
This allows subsystems (like KVM here) to execute code in Hyp-mode with the
MMU disabled.

We initialize other Hyp-mode registers and enables the MMU for Hyp-mode from
the id-mapped hyp initialization code. Afterwards, the HVBAR is changed to
point to KVM Hyp vectors used to catch guest faults and to switch to Hyp mode
to perform a world-switch into a KVM guest.

Also provides memory mapping code to map required code pages, data structures,
and I/O regions  accessed in Hyp mode at the same virtual address as the host
kernel virtual addresses, but which conforms to the architectural requirements
for translations in Hyp mode. This interface is added in arch/arm/kvm/arm_mmu.c
and comprises:
 - create_hyp_mappings(from, to);
 - create_hyp_io_mappings(from, to, phys_addr);
 - free_hyp_pmds();

Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>

1 files changed, 124 insertions, 0 deletions

diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h
index dc678e193417..8875b3f605a7 100644
--- a/arch/arm/include/asm/kvm_arm.h
+++ b/arch/arm/include/asm/kvm_arm.h
@@ -21,4 +21,128 @@
 
 #include <linux/types.h>
 
+/* Hyp Configuration Register (HCR) bits */
+#define HCR_TGE		(1 << 27)
+#define HCR_TVM		(1 << 26)
+#define HCR_TTLB	(1 << 25)
+#define HCR_TPU		(1 << 24)
+#define HCR_TPC		(1 << 23)
+#define HCR_TSW		(1 << 22)
+#define HCR_TAC		(1 << 21)
+#define HCR_TIDCP	(1 << 20)
+#define HCR_TSC		(1 << 19)
+#define HCR_TID3	(1 << 18)
+#define HCR_TID2	(1 << 17)
+#define HCR_TID1	(1 << 16)
+#define HCR_TID0	(1 << 15)
+#define HCR_TWE		(1 << 14)
+#define HCR_TWI		(1 << 13)
+#define HCR_DC		(1 << 12)
+#define HCR_BSU		(3 << 10)
+#define HCR_BSU_IS	(1 << 10)
+#define HCR_FB		(1 << 9)
+#define HCR_VA		(1 << 8)
+#define HCR_VI		(1 << 7)
+#define HCR_VF		(1 << 6)
+#define HCR_AMO		(1 << 5)
+#define HCR_IMO		(1 << 4)
+#define HCR_FMO		(1 << 3)
+#define HCR_PTW		(1 << 2)
+#define HCR_SWIO	(1 << 1)
+#define HCR_VM		1
+
+/*
+ * The bits we set in HCR:
+ * TAC:		Trap ACTLR
+ * TSC:		Trap SMC
+ * TSW:		Trap cache operations by set/way
+ * TWI:		Trap WFI
+ * TIDCP:	Trap L2CTLR/L2ECTLR
+ * BSU_IS:	Upgrade barriers to the inner shareable domain
+ * FB:		Force broadcast of all maintainance operations
+ * AMO:		Override CPSR.A and enable signaling with VA
+ * IMO:		Override CPSR.I and enable signaling with VI
+ * FMO:		Override CPSR.F and enable signaling with VF
+ * SWIO:	Turn set/way invalidates into set/way clean+invalidate
+ */
+#define HCR_GUEST_MASK (HCR_TSC | HCR_TSW | HCR_TWI | HCR_VM | HCR_BSU_IS | \
+			HCR_FB | HCR_TAC | HCR_AMO | HCR_IMO | HCR_FMO | \
+			HCR_SWIO | HCR_TIDCP)
+
+/* Hyp System Control Register (HSCTLR) bits */
+#define HSCTLR_TE	(1 << 30)
+#define HSCTLR_EE	(1 << 25)
+#define HSCTLR_FI	(1 << 21)
+#define HSCTLR_WXN	(1 << 19)
+#define HSCTLR_I	(1 << 12)
+#define HSCTLR_C	(1 << 2)
+#define HSCTLR_A	(1 << 1)
+#define HSCTLR_M	1
+#define HSCTLR_MASK	(HSCTLR_M | HSCTLR_A | HSCTLR_C | HSCTLR_I | \
+			 HSCTLR_WXN | HSCTLR_FI | HSCTLR_EE | HSCTLR_TE)
+
+/* TTBCR and HTCR Registers bits */
+#define TTBCR_EAE	(1 << 31)
+#define TTBCR_IMP	(1 << 30)
+#define TTBCR_SH1	(3 << 28)
+#define TTBCR_ORGN1	(3 << 26)
+#define TTBCR_IRGN1	(3 << 24)
+#define TTBCR_EPD1	(1 << 23)
+#define TTBCR_A1	(1 << 22)
+#define TTBCR_T1SZ	(3 << 16)
+#define TTBCR_SH0	(3 << 12)
+#define TTBCR_ORGN0	(3 << 10)
+#define TTBCR_IRGN0	(3 << 8)
+#define TTBCR_EPD0	(1 << 7)
+#define TTBCR_T0SZ	3
+#define HTCR_MASK	(TTBCR_T0SZ | TTBCR_IRGN0 | TTBCR_ORGN0 | TTBCR_SH0)
+
+/* Hyp Debug Configuration Register bits */
+#define HDCR_TDRA	(1 << 11)
+#define HDCR_TDOSA	(1 << 10)
+#define HDCR_TDA	(1 << 9)
+#define HDCR_TDE	(1 << 8)
+#define HDCR_HPME	(1 << 7)
+#define HDCR_TPM	(1 << 6)
+#define HDCR_TPMCR	(1 << 5)
+#define HDCR_HPMN_MASK	(0x1F)
+
+/*
+ * The architecture supports 40-bit IPA as input to the 2nd stage translations
+ * and PTRS_PER_S2_PGD becomes 1024, because each entry covers 1GB of address
+ * space.
+ */
+#define KVM_PHYS_SHIFT	(40)
+#define KVM_PHYS_SIZE	(1ULL << KVM_PHYS_SHIFT)
+#define KVM_PHYS_MASK	(KVM_PHYS_SIZE - 1ULL)
+#define PTRS_PER_S2_PGD	(1ULL << (KVM_PHYS_SHIFT - 30))
+#define S2_PGD_ORDER	get_order(PTRS_PER_S2_PGD * sizeof(pgd_t))
+#define S2_PGD_SIZE	(1 << S2_PGD_ORDER)
+
+/* Virtualization Translation Control Register (VTCR) bits */
+#define VTCR_SH0	(3 << 12)
+#define VTCR_ORGN0	(3 << 10)
+#define VTCR_IRGN0	(3 << 8)
+#define VTCR_SL0	(3 << 6)
+#define VTCR_S		(1 << 4)
+#define VTCR_T0SZ	(0xf)
+#define VTCR_MASK	(VTCR_SH0 | VTCR_ORGN0 | VTCR_IRGN0 | VTCR_SL0 | \
+			 VTCR_S | VTCR_T0SZ)
+#define VTCR_HTCR_SH	(VTCR_SH0 | VTCR_ORGN0 | VTCR_IRGN0)
+#define VTCR_SL_L2	(0 << 6)	/* Starting-level: 2 */
+#define VTCR_SL_L1	(1 << 6)	/* Starting-level: 1 */
+#define KVM_VTCR_SL0	VTCR_SL_L1
+/* stage-2 input address range defined as 2^(32-T0SZ) */
+#define KVM_T0SZ	(32 - KVM_PHYS_SHIFT)
+#define KVM_VTCR_T0SZ	(KVM_T0SZ & VTCR_T0SZ)
+#define KVM_VTCR_S	((KVM_VTCR_T0SZ << 1) & VTCR_S)
+
+/* Virtualization Translation Table Base Register (VTTBR) bits */
+#if KVM_VTCR_SL0 == VTCR_SL_L2	/* see ARM DDI 0406C: B4-1720 */
+#define VTTBR_X		(14 - KVM_T0SZ)
+#else
+#define VTTBR_X		(5 - KVM_T0SZ)
+#endif
+
+
 #endif /* __ARM_KVM_ARM_H__ */