Patchwork [4/4,v4] kvm: powerpc: use caching attributes as per linux pte

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Submitter Bharat Bhushan
Date Nov. 18, 2013, 5:48 a.m.
Message ID <1384753734-25252-1-git-send-email-Bharat.Bhushan@freescale.com>
Download mbox | patch
Permalink /patch/291944/
State New
Headers show

Comments

Bharat Bhushan - Nov. 18, 2013, 5:48 a.m.
KVM uses same WIM tlb attributes as the corresponding qemu pte.
For this we now search the linux pte for the requested page and
get these cache caching/coherency attributes from pte.

Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
---
v3->v4
 - Corrected returning error by not gating them to rate-limited prints

v2->v3
 - uses lookup_linux_ptep() as lookup_linux_pte() changed to lookup_linux_ptep()

 arch/powerpc/include/asm/kvm_host.h |    2 +-
 arch/powerpc/kvm/booke.c            |    1 +
 arch/powerpc/kvm/e500.h             |    8 ++++--
 arch/powerpc/kvm/e500_mmu_host.c    |   43 +++++++++++++++++++++-------------
 4 files changed, 33 insertions(+), 21 deletions(-)

Patch

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 237d1d2..84758dd 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -546,6 +546,7 @@  struct kvm_vcpu_arch {
 #endif
 	gpa_t paddr_accessed;
 	gva_t vaddr_accessed;
+	pgd_t *pgdir;
 
 	u8 io_gpr; /* GPR used as IO source/target */
 	u8 mmio_is_bigendian;
@@ -603,7 +604,6 @@  struct kvm_vcpu_arch {
 	struct list_head run_list;
 	struct task_struct *run_task;
 	struct kvm_run *kvm_run;
-	pgd_t *pgdir;
 
 	spinlock_t vpa_update_lock;
 	struct kvmppc_vpa vpa;
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 15d0149..57d1dd5 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -729,6 +729,7 @@  int kvmppc_vcpu_run(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
 	thread.debug = current->thread.debug;
 	current->thread.debug = vcpu->arch.shadow_dbg_reg;
 
+	vcpu->arch.pgdir = current->mm->pgd;
 	kvmppc_fix_ee_before_entry();
 
 	ret = __kvmppc_vcpu_run(kvm_run, vcpu);
diff --git a/arch/powerpc/kvm/e500.h b/arch/powerpc/kvm/e500.h
index 4fd9650..a326178 100644
--- a/arch/powerpc/kvm/e500.h
+++ b/arch/powerpc/kvm/e500.h
@@ -31,11 +31,13 @@  enum vcpu_ftr {
 #define E500_TLB_NUM   2
 
 /* entry is mapped somewhere in host TLB */
-#define E500_TLB_VALID		(1 << 0)
+#define E500_TLB_VALID		(1 << 31)
 /* TLB1 entry is mapped by host TLB1, tracked by bitmaps */
-#define E500_TLB_BITMAP		(1 << 1)
+#define E500_TLB_BITMAP		(1 << 30)
 /* TLB1 entry is mapped by host TLB0 */
-#define E500_TLB_TLB0		(1 << 2)
+#define E500_TLB_TLB0		(1 << 29)
+/* bits [6-5] MAS2_X1 and MAS2_X0 and [4-0] bits for WIMGE */
+#define E500_TLB_MAS2_ATTR	(0x7f)
 
 struct tlbe_ref {
 	pfn_t pfn;		/* valid only for TLB0, except briefly */
diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index 41ce60f..e3f8081 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c
@@ -65,15 +65,6 @@  static inline u32 e500_shadow_mas3_attrib(u32 mas3, int usermode)
 	return mas3;
 }
 
-static inline u32 e500_shadow_mas2_attrib(u32 mas2, int usermode)
-{
-#ifdef CONFIG_SMP
-	return (mas2 & MAS2_ATTRIB_MASK) | MAS2_M;
-#else
-	return mas2 & MAS2_ATTRIB_MASK;
-#endif
-}
-
 /*
  * writing shadow tlb entry to host TLB
  */
@@ -249,11 +240,14 @@  static inline int tlbe_is_writable(struct kvm_book3e_206_tlb_entry *tlbe)
 
 static inline void kvmppc_e500_ref_setup(struct tlbe_ref *ref,
 					 struct kvm_book3e_206_tlb_entry *gtlbe,
-					 pfn_t pfn)
+					 pfn_t pfn, unsigned int wimg)
 {
 	ref->pfn = pfn;
 	ref->flags = E500_TLB_VALID;
 
+	/* Use guest supplied MAS2_G and MAS2_E */
+	ref->flags |= (gtlbe->mas2 & MAS2_ATTRIB_MASK) | wimg;
+
 	/* Mark the page accessed */
 	kvm_set_pfn_accessed(pfn);
 
@@ -316,8 +310,7 @@  static void kvmppc_e500_setup_stlbe(
 
 	/* Force IPROT=0 for all guest mappings. */
 	stlbe->mas1 = MAS1_TSIZE(tsize) | get_tlb_sts(gtlbe) | MAS1_VALID;
-	stlbe->mas2 = (gvaddr & MAS2_EPN) |
-		      e500_shadow_mas2_attrib(gtlbe->mas2, pr);
+	stlbe->mas2 = (gvaddr & MAS2_EPN) | (ref->flags & E500_TLB_MAS2_ATTR);
 	stlbe->mas7_3 = ((u64)pfn << PAGE_SHIFT) |
 			e500_shadow_mas3_attrib(gtlbe->mas7_3, pr);
 
@@ -336,6 +329,10 @@  static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
 	unsigned long hva;
 	int pfnmap = 0;
 	int tsize = BOOK3E_PAGESZ_4K;
+	unsigned long tsize_pages = 0;
+	pte_t *ptep;
+	unsigned int wimg = 0;
+	pgd_t *pgdir;
 
 	/*
 	 * Translate guest physical to true physical, acquiring
@@ -398,7 +395,7 @@  static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
 			 */
 
 			for (; tsize > BOOK3E_PAGESZ_4K; tsize -= 2) {
-				unsigned long gfn_start, gfn_end, tsize_pages;
+				unsigned long gfn_start, gfn_end;
 				tsize_pages = 1 << (tsize - 2);
 
 				gfn_start = gfn & ~(tsize_pages - 1);
@@ -440,11 +437,12 @@  static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
 	}
 
 	if (likely(!pfnmap)) {
-		unsigned long tsize_pages = 1 << (tsize + 10 - PAGE_SHIFT);
+		tsize_pages = 1 << (tsize + 10 - PAGE_SHIFT);
 		pfn = gfn_to_pfn_memslot(slot, gfn);
 		if (is_error_noslot_pfn(pfn)) {
-			printk(KERN_ERR "Couldn't get real page for gfn %lx!\n",
-					(long)gfn);
+			if (printk_ratelimit())
+				pr_err("%s: real page not found for gfn %lx\n",
+				       __func__, (long)gfn);
 			return -EINVAL;
 		}
 
@@ -453,7 +451,18 @@  static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500,
 		gvaddr &= ~((tsize_pages << PAGE_SHIFT) - 1);
 	}
 
-	kvmppc_e500_ref_setup(ref, gtlbe, pfn);
+
+	pgdir = vcpu_e500->vcpu.arch.pgdir;
+	ptep = lookup_linux_ptep(pgdir, hva, &tsize_pages);
+	if (pte_present(*ptep))
+		wimg = (*ptep >> PTE_WIMGE_SHIFT) & MAS2_WIMGE_MASK;
+	else {
+		if (printk_ratelimit())
+			pr_err("%s: pte not present: gfn %lx, pfn %lx\n",
+				__func__, (long)gfn, pfn);
+		return -EINVAL;
+	}
+	kvmppc_e500_ref_setup(ref, gtlbe, pfn, wimg);
 
 	kvmppc_e500_setup_stlbe(&vcpu_e500->vcpu, gtlbe, tsize,
 				ref, gvaddr, stlbe);