powerpc/kvm: Sync guest visible MMU state

Currently userspace has no chance to find out which virtual address space we're
in and resolve addresses. While that is a big problem for migration, it's also
unpleasent when debugging, as gdb and the monitor don't work on virtual
addresses.

This patch exports enough of the MMU segment state to userspace to make
debugging work and thus also includes the groundwork for migration.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

4 files changed, 77 insertions, 15 deletions

diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 42037d46a41..3e294bd9b8c 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -281,6 +281,7 @@ void kvmppc_core_deliver_interrupts(struct kvm_vcpu *vcpu)
 
 void kvmppc_set_pvr(struct kvm_vcpu *vcpu, u32 pvr)
 {
+	vcpu->arch.hflags &= ~BOOK3S_HFLAG_SLB;
 	vcpu->arch.pvr = pvr;
 	if ((pvr >= 0x330000) && (pvr < 0x70330000)) {
 		kvmppc_mmu_book3s_64_init(vcpu);
@@ -762,14 +763,62 @@ int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
                                   struct kvm_sregs *sregs)
 {
+	struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
+	int i;
+
 	sregs->pvr = vcpu->arch.pvr;
+
+	sregs->u.s.sdr1 = to_book3s(vcpu)->sdr1;
+	if (vcpu->arch.hflags & BOOK3S_HFLAG_SLB) {
+		for (i = 0; i < 64; i++) {
+			sregs->u.s.ppc64.slb[i].slbe = vcpu3s->slb[i].orige | i;
+			sregs->u.s.ppc64.slb[i].slbv = vcpu3s->slb[i].origv;
+		}
+	} else {
+		for (i = 0; i < 16; i++) {
+			sregs->u.s.ppc32.sr[i] = vcpu3s->sr[i].raw;
+			sregs->u.s.ppc32.sr[i] = vcpu3s->sr[i].raw;
+		}
+		for (i = 0; i < 8; i++) {
+			sregs->u.s.ppc32.ibat[i] = vcpu3s->ibat[i].raw;
+			sregs->u.s.ppc32.dbat[i] = vcpu3s->dbat[i].raw;
+		}
+	}
 	return 0;
 }
 
 int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
                                   struct kvm_sregs *sregs)
 {
+	struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
+	int i;
+
 	kvmppc_set_pvr(vcpu, sregs->pvr);
+
+	vcpu3s->sdr1 = sregs->u.s.sdr1;
+	if (vcpu->arch.hflags & BOOK3S_HFLAG_SLB) {
+		for (i = 0; i < 64; i++) {
+			vcpu->arch.mmu.slbmte(vcpu, sregs->u.s.ppc64.slb[i].slbv,
+						    sregs->u.s.ppc64.slb[i].slbe);
+		}
+	} else {
+		for (i = 0; i < 16; i++) {
+			vcpu->arch.mmu.mtsrin(vcpu, i, sregs->u.s.ppc32.sr[i]);
+		}
+		for (i = 0; i < 8; i++) {
+			kvmppc_set_bat(vcpu, &(vcpu3s->ibat[i]), false,
+				       (u32)sregs->u.s.ppc32.ibat[i]);
+			kvmppc_set_bat(vcpu, &(vcpu3s->ibat[i]), true,
+				       (u32)(sregs->u.s.ppc32.ibat[i] >> 32));
+			kvmppc_set_bat(vcpu, &(vcpu3s->dbat[i]), false,
+				       (u32)sregs->u.s.ppc32.dbat[i]);
+			kvmppc_set_bat(vcpu, &(vcpu3s->dbat[i]), true,
+				       (u32)(sregs->u.s.ppc32.dbat[i] >> 32));
+		}
+	}
+
+	/* Flush the MMU after messing with the segments */
+	kvmppc_mmu_pte_flush(vcpu, 0, 0);
 	return 0;
 }
 
diff --git a/arch/powerpc/kvm/book3s_64_emulate.c b/arch/powerpc/kvm/book3s_64_emulate.c
index c343e67306e..1027eac6d47 100644
--- a/arch/powerpc/kvm/book3s_64_emulate.c
+++ b/arch/powerpc/kvm/book3s_64_emulate.c
@@ -185,7 +185,27 @@ int kvmppc_core_emulate_op(struct kvm_run *run, struct kvm_vcpu *vcpu,
 	return emulated;
 }
 
-static void kvmppc_write_bat(struct kvm_vcpu *vcpu, int sprn, u64 val)
+void kvmppc_set_bat(struct kvm_vcpu *vcpu, struct kvmppc_bat *bat, bool upper,
+                    u32 val)
+{
+	if (upper) {
+		/* Upper BAT */
+		u32 bl = (val >> 2) & 0x7ff;
+		bat->bepi_mask = (~bl << 17);
+		bat->bepi = val & 0xfffe0000;
+		bat->vs = (val & 2) ? 1 : 0;
+		bat->vp = (val & 1) ? 1 : 0;
+		bat->raw = (bat->raw & 0xffffffff00000000ULL) | val;
+	} else {
+		/* Lower BAT */
+		bat->brpn = val & 0xfffe0000;
+		bat->wimg = (val >> 3) & 0xf;
+		bat->pp = val & 3;
+		bat->raw = (bat->raw & 0x00000000ffffffffULL) | ((u64)val << 32);
+	}
+}
+
+static void kvmppc_write_bat(struct kvm_vcpu *vcpu, int sprn, u32 val)
 {
 	struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
 	struct kvmppc_bat *bat;
@@ -207,19 +227,7 @@ static void kvmppc_write_bat(struct kvm_vcpu *vcpu, int sprn, u64 val)
 		BUG();
 	}
 
-	if (!(sprn % 2)) {
-		/* Upper BAT */
-		u32 bl = (val >> 2) & 0x7ff;
-		bat->bepi_mask = (~bl << 17);
-		bat->bepi = val & 0xfffe0000;
-		bat->vs = (val & 2) ? 1 : 0;
-		bat->vp = (val & 1) ? 1 : 0;
-	} else {
-		/* Lower BAT */
-		bat->brpn = val & 0xfffe0000;
-		bat->wimg = (val >> 3) & 0xf;
-		bat->pp = val & 3;
-	}
+	kvmppc_set_bat(vcpu, bat, !(sprn % 2), val);
 }
 
 int kvmppc_core_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs)
@@ -243,7 +251,7 @@ int kvmppc_core_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs)
 	case SPRN_IBAT4U ... SPRN_IBAT7L:
 	case SPRN_DBAT0U ... SPRN_DBAT3L:
 	case SPRN_DBAT4U ... SPRN_DBAT7L:
-		kvmppc_write_bat(vcpu, sprn, vcpu->arch.gpr[rs]);
+		kvmppc_write_bat(vcpu, sprn, (u32)vcpu->arch.gpr[rs]);
 		/* BAT writes happen so rarely that we're ok to flush
 		 * everything here */
 		kvmppc_mmu_pte_flush(vcpu, 0, 0);
diff --git a/arch/powerpc/kvm/book3s_64_mmu.c b/arch/powerpc/kvm/book3s_64_mmu.c
index a31f9c677d2..5598f88f142 100644
--- a/arch/powerpc/kvm/book3s_64_mmu.c
+++ b/arch/powerpc/kvm/book3s_64_mmu.c
@@ -473,4 +473,6 @@ void kvmppc_mmu_book3s_64_init(struct kvm_vcpu *vcpu)
 	mmu->esid_to_vsid = kvmppc_mmu_book3s_64_esid_to_vsid;
 	mmu->ea_to_vp = kvmppc_mmu_book3s_64_ea_to_vp;
 	mmu->is_dcbz32 = kvmppc_mmu_book3s_64_is_dcbz32;
+
+	vcpu->arch.hflags |= BOOK3S_HFLAG_SLB;
 }
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 692c3709011..d82551efbfb 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -144,6 +144,9 @@ int kvm_dev_ioctl_check_extension(long ext)
 	int r;
 
 	switch (ext) {
+	case KVM_CAP_PPC_SEGSTATE:
+		r = 1;
+		break;
 	case KVM_CAP_COALESCED_MMIO:
 		r = KVM_COALESCED_MMIO_PAGE_OFFSET;
 		break;