[RFC PATCH] KVM: PPC: BOOK3S: HV: THP support for guest

Aneesh Kumar K.V aneesh.kumar at linux.vnet.ibm.com
Mon May 5 03:30:16 EST 2014


Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/kvm_book3s_64.h | 146 ++++++++++++++++++++++++++-----
 arch/powerpc/kvm/book3s_hv.c             |   7 ++
 2 files changed, 130 insertions(+), 23 deletions(-)

diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h b/arch/powerpc/include/asm/kvm_book3s_64.h
index 51388befeddb..f03ea8f90576 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -77,34 +77,122 @@ static inline long try_lock_hpte(unsigned long *hpte, unsigned long bits)
 	return old == 0;
 }
 
+static inline int __hpte_actual_psize(unsigned int lp, int psize)
+{
+	int i, shift;
+	unsigned int mask;
+
+	/* start from 1 ignoring MMU_PAGE_4K */
+	for (i = 1; i < MMU_PAGE_COUNT; i++) {
+
+		/* invalid penc */
+		if (mmu_psize_defs[psize].penc[i] == -1)
+			continue;
+		/*
+		 * encoding bits per actual page size
+		 *        PTE LP     actual page size
+		 *    rrrr rrrz		>=8KB
+		 *    rrrr rrzz		>=16KB
+		 *    rrrr rzzz		>=32KB
+		 *    rrrr zzzz		>=64KB
+		 * .......
+		 */
+		shift = mmu_psize_defs[i].shift - LP_SHIFT;
+		if (shift > LP_BITS)
+			shift = LP_BITS;
+		mask = (1 << shift) - 1;
+		if ((lp & mask) == mmu_psize_defs[psize].penc[i])
+			return i;
+	}
+	return -1;
+}
+
 static inline unsigned long compute_tlbie_rb(unsigned long v, unsigned long r,
 					     unsigned long pte_index)
 {
-	unsigned long rb, va_low;
+	int b_size, a_size;
+	unsigned int penc;
+	unsigned long rb = 0, va_low, sllp;
+	unsigned int lp = (r >> LP_SHIFT) & ((1 << LP_BITS) - 1);
+
+	if (!(v & HPTE_V_LARGE)) {
+		/* both base and actual psize is 4k */
+		b_size = MMU_PAGE_4K;
+		a_size = MMU_PAGE_4K;
+	} else {
+		for (b_size = 0; b_size < MMU_PAGE_COUNT; b_size++) {
+
+			/* valid entries have a shift value */
+			if (!mmu_psize_defs[b_size].shift)
+				continue;
 
+			a_size = __hpte_actual_psize(lp, b_size);
+			if (a_size != -1)
+				break;
+		}
+	}
+	/*
+	 * Ignore the top 14 bits of va
+	 * v have top two bits covering segment size, hence move
+	 * by 16 bits, Also clear the lower HPTE_V_AVPN_SHIFT (7) bits.
+	 * AVA field in v also have the lower 23 bits ignored.
+	 * For base page size 4K we need 14 .. 65 bits (so need to
+	 * collect extra 11 bits)
+	 * For others we need 14..14+i
+	 */
+	/* This covers 14..54 bits of va*/
 	rb = (v & ~0x7fUL) << 16;		/* AVA field */
+	/*
+	 * AVA in v had cleared lower 23 bits. We need to derive
+	 * that from pteg index
+	 */
 	va_low = pte_index >> 3;
 	if (v & HPTE_V_SECONDARY)
 		va_low = ~va_low;
-	/* xor vsid from AVA */
+	/*
+	 * get the vpn bits from va_low using reverse of hashing.
+	 * In v we have va with 23 bits dropped and then left shifted
+	 * HPTE_V_AVPN_SHIFT (7) bits. Now to find vsid we need
+	 * right shift it with (SID_SHIFT - (23 - 7))
+	 */
 	if (!(v & HPTE_V_1TB_SEG))
-		va_low ^= v >> 12;
+		va_low ^= v >> (SID_SHIFT - 16);
 	else
-		va_low ^= v >> 24;
+		va_low ^= v >> (SID_SHIFT_1T - 16);
 	va_low &= 0x7ff;
-	if (v & HPTE_V_LARGE) {
-		rb |= 1;			/* L field */
-		if (cpu_has_feature(CPU_FTR_ARCH_206) &&
-		    (r & 0xff000)) {
-			/* non-16MB large page, must be 64k */
-			/* (masks depend on page size) */
-			rb |= 0x1000;		/* page encoding in LP field */
-			rb |= (va_low & 0x7f) << 16; /* 7b of VA in AVA/LP field */
-			rb |= ((va_low << 4) & 0xf0);	/* AVAL field (P7 doesn't seem to care) */
-		}
-	} else {
-		/* 4kB page */
-		rb |= (va_low & 0x7ff) << 12;	/* remaining 11b of VA */
+
+	switch (b_size) {
+	case MMU_PAGE_4K:
+		sllp = ((mmu_psize_defs[a_size].sllp & SLB_VSID_L) >> 6) |
+			((mmu_psize_defs[a_size].sllp & SLB_VSID_LP) >> 4);
+		rb |= sllp << 5;	/*  AP field */
+		rb |= (va_low & 0x7ff) << 12;	/* remaining 11 bits of AVA */
+		break;
+	default:
+	{
+		int aval_shift;
+		/*
+		 * remaining 7bits of AVA/LP fields
+		 * Also contain the rr bits of LP
+		 */
+		rb |= (va_low & 0x7f) << 16;
+		/*
+		 * Now clear not needed LP bits based on actual psize
+		 */
+		rb &= ~((1ul << mmu_psize_defs[a_size].shift) - 1);
+		/*
+		 * AVAL field 58..77 - base_page_shift bits of va
+		 * we have space for 58..64 bits, Missing bits should
+		 * be zero filled. +1 is to take care of L bit shift
+		 */
+		aval_shift = 64 - (77 - mmu_psize_defs[b_size].shift) + 1;
+		rb |= ((va_low << aval_shift) & 0xfe);
+
+		rb |= 1;		/* L field */
+		penc = mmu_psize_defs[b_size].penc[a_size];
+		rb |= penc << 12;	/* LP field */
+		break;
+	}
 	}
 	rb |= (v >> 54) & 0x300;		/* B field */
 	return rb;
@@ -112,14 +200,26 @@ static inline unsigned long compute_tlbie_rb(unsigned long v, unsigned long r,
 
 static inline unsigned long hpte_page_size(unsigned long h, unsigned long l)
 {
+	int size, a_size;
+	/* Look at the 8 bit LP value */
+	unsigned int lp = (l >> LP_SHIFT) & ((1 << LP_BITS) - 1);
+
 	/* only handle 4k, 64k and 16M pages for now */
 	if (!(h & HPTE_V_LARGE))
-		return 1ul << 12;		/* 4k page */
-	if ((l & 0xf000) == 0x1000 && cpu_has_feature(CPU_FTR_ARCH_206))
-		return 1ul << 16;		/* 64k page */
-	if ((l & 0xff000) == 0)
-		return 1ul << 24;		/* 16M page */
-	return 0;				/* error */
+		return 1ul << 12;
+	else {
+		for (size = 0; size < MMU_PAGE_COUNT; size++) {
+			/* valid entries have a shift value */
+			if (!mmu_psize_defs[size].shift)
+				continue;
+
+			a_size = __hpte_actual_psize(lp, size);
+			if (a_size != -1)
+				return 1ul << mmu_psize_defs[a_size].shift;
+		}
+
+	}
+	return 0;
 }
 
 static inline unsigned long hpte_rpn(unsigned long ptel, unsigned long psize)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 8227dba5af0f..a38d3289320a 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1949,6 +1949,13 @@ static void kvmppc_add_seg_page_size(struct kvm_ppc_one_seg_page_size **sps,
 	 * support pte_enc here
 	 */
 	(*sps)->enc[0].pte_enc = def->penc[linux_psize];
+	/*
+	 * Add 16MB MPSS support
+	 */
+	if (linux_psize != MMU_PAGE_16M) {
+		(*sps)->enc[1].page_shift = 24;
+		(*sps)->enc[1].pte_enc = def->penc[MMU_PAGE_16M];
+	}
 	(*sps)++;
 }
 
-- 
1.9.1



More information about the Linuxppc-dev mailing list