KVM: PPC: Make shared struct aka magic page guest endian

The shared (magic) page is a data structure that contains often used
supervisor privileged SPRs accessible via memory to the user to reduce
the number of exits we have to take to read/write them.

When we actually share this structure with the guest we have to maintain
it in guest endianness, because some of the patch tricks only work with
native endian load/store operations.

Since we only share the structure with either host or guest in little
endian on book3s_64 pr mode, we don't have to worry about booke or book3s hv.

For booke, the shared struct stays big endian. For book3s_64 hv we maintain
the struct in host native endian, since it never gets shared with the guest.

For book3s_64 pr we introduce a variable that tells us which endianness the
shared struct is in and route every access to it through helper inline
functions that evaluate this variable.

Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 11 insertions, 10 deletions

diff --git a/arch/powerpc/kvm/book3s_32_mmu.c b/arch/powerpc/kvm/book3s_32_mmu.c
index 0e42b167da0b..628d90ed417d 100644
--- a/arch/powerpc/kvm/book3s_32_mmu.c
+++ b/arch/powerpc/kvm/book3s_32_mmu.c
@@ -91,7 +91,7 @@ static int kvmppc_mmu_book3s_32_esid_to_vsid(struct kvm_vcpu *vcpu, ulong esid,
 
 static u32 find_sr(struct kvm_vcpu *vcpu, gva_t eaddr)
 {
-	return vcpu->arch.shared->sr[(eaddr >> 28) & 0xf];
+	return kvmppc_get_sr(vcpu, (eaddr >> 28) & 0xf);
 }
 
 static u64 kvmppc_mmu_book3s_32_ea_to_vp(struct kvm_vcpu *vcpu, gva_t eaddr,
@@ -160,7 +160,7 @@ static int kvmppc_mmu_book3s_32_xlate_bat(struct kvm_vcpu *vcpu, gva_t eaddr,
 		else
 			bat = &vcpu_book3s->ibat[i];
 
-		if (vcpu->arch.shared->msr & MSR_PR) {
+		if (kvmppc_get_msr(vcpu) & MSR_PR) {
 			if (!bat->vp)
 				continue;
 		} else {
@@ -242,8 +242,8 @@ static int kvmppc_mmu_book3s_32_xlate_pte(struct kvm_vcpu *vcpu, gva_t eaddr,
 			pte->raddr = (pte1 & ~(0xFFFULL)) | (eaddr & 0xFFF);
 			pp = pte1 & 3;
 
-			if ((sr_kp(sre) &&  (vcpu->arch.shared->msr & MSR_PR)) ||
-			    (sr_ks(sre) && !(vcpu->arch.shared->msr & MSR_PR)))
+			if ((sr_kp(sre) &&  (kvmppc_get_msr(vcpu) & MSR_PR)) ||
+			    (sr_ks(sre) && !(kvmppc_get_msr(vcpu) & MSR_PR)))
 				pp |= 4;
 
 			pte->may_write = false;
@@ -320,7 +320,7 @@ static int kvmppc_mmu_book3s_32_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
 	/* Magic page override */
 	if (unlikely(mp_ea) &&
 	    unlikely((eaddr & ~0xfffULL) == (mp_ea & ~0xfffULL)) &&
-	    !(vcpu->arch.shared->msr & MSR_PR)) {
+	    !(kvmppc_get_msr(vcpu) & MSR_PR)) {
 		pte->vpage = kvmppc_mmu_book3s_32_ea_to_vp(vcpu, eaddr, data);
 		pte->raddr = vcpu->arch.magic_page_pa | (pte->raddr & 0xfff);
 		pte->raddr &= KVM_PAM;
@@ -345,13 +345,13 @@ static int kvmppc_mmu_book3s_32_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
 
 static u32 kvmppc_mmu_book3s_32_mfsrin(struct kvm_vcpu *vcpu, u32 srnum)
 {
-	return vcpu->arch.shared->sr[srnum];
+	return kvmppc_get_sr(vcpu, srnum);
 }
 
 static void kvmppc_mmu_book3s_32_mtsrin(struct kvm_vcpu *vcpu, u32 srnum,
 					ulong value)
 {
-	vcpu->arch.shared->sr[srnum] = value;
+	kvmppc_set_sr(vcpu, srnum, value);
 	kvmppc_mmu_map_segment(vcpu, srnum << SID_SHIFT);
 }
 
@@ -371,8 +371,9 @@ static int kvmppc_mmu_book3s_32_esid_to_vsid(struct kvm_vcpu *vcpu, ulong esid,
 	ulong ea = esid << SID_SHIFT;
 	u32 sr;
 	u64 gvsid = esid;
+	u64 msr = kvmppc_get_msr(vcpu);
 
-	if (vcpu->arch.shared->msr & (MSR_DR|MSR_IR)) {
+	if (msr & (MSR_DR|MSR_IR)) {
 		sr = find_sr(vcpu, ea);
 		if (sr_valid(sr))
 			gvsid = sr_vsid(sr);
@@ -381,7 +382,7 @@ static int kvmppc_mmu_book3s_32_esid_to_vsid(struct kvm_vcpu *vcpu, ulong esid,
 	/* In case we only have one of MSR_IR or MSR_DR set, let's put
 	   that in the real-mode context (and hope RM doesn't access
 	   high memory) */
-	switch (vcpu->arch.shared->msr & (MSR_DR|MSR_IR)) {
+	switch (msr & (MSR_DR|MSR_IR)) {
 	case 0:
 		*vsid = VSID_REAL | esid;
 		break;
@@ -401,7 +402,7 @@ static int kvmppc_mmu_book3s_32_esid_to_vsid(struct kvm_vcpu *vcpu, ulong esid,
 		BUG();
 	}
 
-	if (vcpu->arch.shared->msr & MSR_PR)
+	if (msr & MSR_PR)
 		*vsid |= VSID_PR;
 
 	return 0;