Patchwork [4/4,v3] kvm: powerpc: use caching attributes as per linux pte

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Submitter Bharat Bhushan
Date Nov. 15, 2013, 5:31 a.m.
Message ID <1384493476-18036-5-git-send-email-Bharat.Bhushan@freescale.com>
Download mbox | patch
Permalink /patch/291474/
State New
Headers show

Comments

Bharat Bhushan - Nov. 15, 2013, 5:31 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>
---
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    |   39 ++++++++++++++++++++--------------
 4 files changed, 30 insertions(+), 20 deletions(-)
Scott Wood - Nov. 15, 2013, 8:35 p.m.
On Fri, 2013-11-15 at 11:01 +0530, Bharat Bhushan wrote:
> @@ -440,9 +437,9 @@ 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)) {
> +		if (is_error_noslot_pfn(pfn) && printk_ratelimit()) {
>  			printk(KERN_ERR "Couldn't get real page for gfn %lx!\n",
>  					(long)gfn);
>  			return -EINVAL;

The "return -EINVAL" shouldn't be affected by printk_ratelimit().

> @@ -453,7 +450,17 @@ 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()) {
> +		printk(KERN_ERR "%s: pte not present: gfn %lx, pfn %lx\n",
> +				__func__, (long)gfn, pfn);
> +		return -EINVAL;
> +	}

Likewise.

-Scott



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Bharat Bhushan - Nov. 18, 2013, 5:56 a.m.
> -----Original Message-----

> From: Wood Scott-B07421

> Sent: Saturday, November 16, 2013 2:06 AM

> To: Bhushan Bharat-R65777

> Cc: paulus@samba.org; agraf@suse.de; kvm-ppc@vger.kernel.org;

> kvm@vger.kernel.org; Yoder Stuart-B08248; Bhushan Bharat-R65777

> Subject: Re: [PATCH 4/4 v3] kvm: powerpc: use caching attributes as per linux

> pte

> 

> On Fri, 2013-11-15 at 11:01 +0530, Bharat Bhushan wrote:

> > @@ -440,9 +437,9 @@ 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)) {

> > +		if (is_error_noslot_pfn(pfn) && printk_ratelimit()) {

> >  			printk(KERN_ERR "Couldn't get real page for gfn %lx!\n",

> >  					(long)gfn);

> >  			return -EINVAL;

> 

> The "return -EINVAL" shouldn't be affected by printk_ratelimit().


Sent updated patch correcting this. I sent only this patch of the patch series
hoping no more changed needed in previous patches :)

-Bharat

> 

> > @@ -453,7 +450,17 @@ 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()) {

> > +		printk(KERN_ERR "%s: pte not present: gfn %lx, pfn %lx\n",

> > +				__func__, (long)gfn, pfn);

> > +		return -EINVAL;

> > +	}

> 

> Likewise.

> 

> -Scott

>

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..4f0400a 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);
@@ -440,9 +437,9 @@  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)) {
+		if (is_error_noslot_pfn(pfn) && printk_ratelimit()) {
 			printk(KERN_ERR "Couldn't get real page for gfn %lx!\n",
 					(long)gfn);
 			return -EINVAL;
@@ -453,7 +450,17 @@  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()) {
+		printk(KERN_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);