Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 223 insertions, 0 deletions

diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c
new file mode 100644
index 0000000000..2415722c01
--- /dev/null
+++ b/arch/riscv/kvm/vcpu_exit.c
@@ -0,0 +1,223 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *     Anup Patel <anup.patel@wdc.com>
+ */
+
+#include <linux/kvm_host.h>
+#include <asm/csr.h>
+#include <asm/insn-def.h>
+
+static int gstage_page_fault(struct kvm_vcpu *vcpu, struct kvm_run *run,
+			     struct kvm_cpu_trap *trap)
+{
+	struct kvm_memory_slot *memslot;
+	unsigned long hva, fault_addr;
+	bool writable;
+	gfn_t gfn;
+	int ret;
+
+	fault_addr = (trap->htval << 2) | (trap->stval & 0x3);
+	gfn = fault_addr >> PAGE_SHIFT;
+	memslot = gfn_to_memslot(vcpu->kvm, gfn);
+	hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
+
+	if (kvm_is_error_hva(hva) ||
+	    (trap->scause == EXC_STORE_GUEST_PAGE_FAULT && !writable)) {
+		switch (trap->scause) {
+		case EXC_LOAD_GUEST_PAGE_FAULT:
+			return kvm_riscv_vcpu_mmio_load(vcpu, run,
+							fault_addr,
+							trap->htinst);
+		case EXC_STORE_GUEST_PAGE_FAULT:
+			return kvm_riscv_vcpu_mmio_store(vcpu, run,
+							 fault_addr,
+							 trap->htinst);
+		default:
+			return -EOPNOTSUPP;
+		};
+	}
+
+	ret = kvm_riscv_gstage_map(vcpu, memslot, fault_addr, hva,
+		(trap->scause == EXC_STORE_GUEST_PAGE_FAULT) ? true : false);
+	if (ret < 0)
+		return ret;
+
+	return 1;
+}
+
+/**
+ * kvm_riscv_vcpu_unpriv_read -- Read machine word from Guest memory
+ *
+ * @vcpu: The VCPU pointer
+ * @read_insn: Flag representing whether we are reading instruction
+ * @guest_addr: Guest address to read
+ * @trap: Output pointer to trap details
+ */
+unsigned long kvm_riscv_vcpu_unpriv_read(struct kvm_vcpu *vcpu,
+					 bool read_insn,
+					 unsigned long guest_addr,
+					 struct kvm_cpu_trap *trap)
+{
+	register unsigned long taddr asm("a0") = (unsigned long)trap;
+	register unsigned long ttmp asm("a1");
+	unsigned long flags, val, tmp, old_stvec, old_hstatus;
+
+	local_irq_save(flags);
+
+	old_hstatus = csr_swap(CSR_HSTATUS, vcpu->arch.guest_context.hstatus);
+	old_stvec = csr_swap(CSR_STVEC, (ulong)&__kvm_riscv_unpriv_trap);
+
+	if (read_insn) {
+		/*
+		 * HLVX.HU instruction
+		 * 0110010 00011 rs1 100 rd 1110011
+		 */
+		asm volatile ("\n"
+			".option push\n"
+			".option norvc\n"
+			"add %[ttmp], %[taddr], 0\n"
+			HLVX_HU(%[val], %[addr])
+			"andi %[tmp], %[val], 3\n"
+			"addi %[tmp], %[tmp], -3\n"
+			"bne %[tmp], zero, 2f\n"
+			"addi %[addr], %[addr], 2\n"
+			HLVX_HU(%[tmp], %[addr])
+			"sll %[tmp], %[tmp], 16\n"
+			"add %[val], %[val], %[tmp]\n"
+			"2:\n"
+			".option pop"
+		: [val] "=&r" (val), [tmp] "=&r" (tmp),
+		  [taddr] "+&r" (taddr), [ttmp] "+&r" (ttmp),
+		  [addr] "+&r" (guest_addr) : : "memory");
+
+		if (trap->scause == EXC_LOAD_PAGE_FAULT)
+			trap->scause = EXC_INST_PAGE_FAULT;
+	} else {
+		/*
+		 * HLV.D instruction
+		 * 0110110 00000 rs1 100 rd 1110011
+		 *
+		 * HLV.W instruction
+		 * 0110100 00000 rs1 100 rd 1110011
+		 */
+		asm volatile ("\n"
+			".option push\n"
+			".option norvc\n"
+			"add %[ttmp], %[taddr], 0\n"
+#ifdef CONFIG_64BIT
+			HLV_D(%[val], %[addr])
+#else
+			HLV_W(%[val], %[addr])
+#endif
+			".option pop"
+		: [val] "=&r" (val),
+		  [taddr] "+&r" (taddr), [ttmp] "+&r" (ttmp)
+		: [addr] "r" (guest_addr) : "memory");
+	}
+
+	csr_write(CSR_STVEC, old_stvec);
+	csr_write(CSR_HSTATUS, old_hstatus);
+
+	local_irq_restore(flags);
+
+	return val;
+}
+
+/**
+ * kvm_riscv_vcpu_trap_redirect -- Redirect trap to Guest
+ *
+ * @vcpu: The VCPU pointer
+ * @trap: Trap details
+ */
+void kvm_riscv_vcpu_trap_redirect(struct kvm_vcpu *vcpu,
+				  struct kvm_cpu_trap *trap)
+{
+	unsigned long vsstatus = csr_read(CSR_VSSTATUS);
+
+	/* Change Guest SSTATUS.SPP bit */
+	vsstatus &= ~SR_SPP;
+	if (vcpu->arch.guest_context.sstatus & SR_SPP)
+		vsstatus |= SR_SPP;
+
+	/* Change Guest SSTATUS.SPIE bit */
+	vsstatus &= ~SR_SPIE;
+	if (vsstatus & SR_SIE)
+		vsstatus |= SR_SPIE;
+
+	/* Clear Guest SSTATUS.SIE bit */
+	vsstatus &= ~SR_SIE;
+
+	/* Update Guest SSTATUS */
+	csr_write(CSR_VSSTATUS, vsstatus);
+
+	/* Update Guest SCAUSE, STVAL, and SEPC */
+	csr_write(CSR_VSCAUSE, trap->scause);
+	csr_write(CSR_VSTVAL, trap->stval);
+	csr_write(CSR_VSEPC, trap->sepc);
+
+	/* Set Guest PC to Guest exception vector */
+	vcpu->arch.guest_context.sepc = csr_read(CSR_VSTVEC);
+
+	/* Set Guest privilege mode to supervisor */
+	vcpu->arch.guest_context.sstatus |= SR_SPP;
+}
+
+/*
+ * Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
+ * proper exit to userspace.
+ */
+int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
+			struct kvm_cpu_trap *trap)
+{
+	int ret;
+
+	/* If we got host interrupt then do nothing */
+	if (trap->scause & CAUSE_IRQ_FLAG)
+		return 1;
+
+	/* Handle guest traps */
+	ret = -EFAULT;
+	run->exit_reason = KVM_EXIT_UNKNOWN;
+	switch (trap->scause) {
+	case EXC_INST_ILLEGAL:
+	case EXC_LOAD_MISALIGNED:
+	case EXC_STORE_MISALIGNED:
+		if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV) {
+			kvm_riscv_vcpu_trap_redirect(vcpu, trap);
+			ret = 1;
+		}
+		break;
+	case EXC_VIRTUAL_INST_FAULT:
+		if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV)
+			ret = kvm_riscv_vcpu_virtual_insn(vcpu, run, trap);
+		break;
+	case EXC_INST_GUEST_PAGE_FAULT:
+	case EXC_LOAD_GUEST_PAGE_FAULT:
+	case EXC_STORE_GUEST_PAGE_FAULT:
+		if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV)
+			ret = gstage_page_fault(vcpu, run, trap);
+		break;
+	case EXC_SUPERVISOR_SYSCALL:
+		if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV)
+			ret = kvm_riscv_vcpu_sbi_ecall(vcpu, run);
+		break;
+	default:
+		break;
+	}
+
+	/* Print details in-case of error */
+	if (ret < 0) {
+		kvm_err("VCPU exit error %d\n", ret);
+		kvm_err("SEPC=0x%lx SSTATUS=0x%lx HSTATUS=0x%lx\n",
+			vcpu->arch.guest_context.sepc,
+			vcpu->arch.guest_context.sstatus,
+			vcpu->arch.guest_context.hstatus);
+		kvm_err("SCAUSE=0x%lx STVAL=0x%lx HTVAL=0x%lx HTINST=0x%lx\n",
+			trap->scause, trap->stval, trap->htval, trap->htinst);
+	}
+
+	return ret;
+}