Re: [PATCH v12 08/20] KVM: pfncache: allow a cache to be activated with a fixed (userspace) HVA

On 14/02/2024 16:20, Sean Christopherson wrote:

On Wed, Feb 14, 2024, Paul Durrant wrote:

...

On 07/02/2024 04:03, Sean Christopherson wrote:

...

+s390 folks (question on kvm_is_error_gpa() for ya) But! kvm_is_error_gpa() already exists, and it very, very sneakily does a memslot lookup and checks for a valid HVA.

s390 people, any objection to renaming kvm_is_error_gpa() to something like kvm_gpa_has_memslot() or kvm_gpa_is_in_memslot()? s390 is the only code that uses the existing helper.

That would both to free up the name to pair with kvm_is_error_hva(), and would make it obvious what the helper does; I was quite surprised that "error" means "is covered by a valid memslot".

Seemingly no response to this; I'll define a local helper rather than re-working the open-coded tests to check against INVALID_GPA. This can then be trivially replaced if need be.

How about we force a decision with a patch? This should be easy enough to slot in, and I would be quite surprised if s390 is overly attached to kvm_is_error_gpa().

Ok. I'll slot that in.

From: Sean Christopherson seanjc@google.com Date: Wed, 14 Feb 2024 08:05:49 -0800 Subject: [PATCH] KVM: s390: Refactor kvm_is_error_gpa() into kvm_is_gpa_in_memslot()

Rename kvm_is_error_gpa() to kvm_is_gpa_in_memslot() and invert the polarity accordingly in order to (a) free up kvm_is_error_gpa() to match with kvm_is_error_{hva,page}(), and (b) to make it more obvious that the helper is doing a memslot lookup, i.e. not simply checking for INVALID_GPA.

No functional change intended.

Signed-off-by: Sean Christopherson seanjc@google.com

arch/s390/kvm/diag.c | 2 +- arch/s390/kvm/gaccess.c | 14 +++++++------- arch/s390/kvm/kvm-s390.c | 4 ++-- arch/s390/kvm/priv.c | 4 ++-- arch/s390/kvm/sigp.c | 2 +- include/linux/kvm_host.h | 4 ++-- 6 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/arch/s390/kvm/diag.c b/arch/s390/kvm/diag.c index 3c65b8258ae6..2a32438e09ce 100644 --- a/arch/s390/kvm/diag.c +++ b/arch/s390/kvm/diag.c @@ -102,7 +102,7 @@ static int __diag_page_ref_service(struct kvm_vcpu *vcpu) parm.token_addr & 7 || parm.zarch != 0x8000000000000000ULL) return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

• if (kvm_is_error_gpa(vcpu->kvm, parm.token_addr))
  

• if (!kvm_is_gpa_in_memslot(vcpu->kvm, parm.token_addr))
  return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
  

vcpu->arch.pfault_token = parm.token_addr; diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c index 5bfcc50c1a68..415c99649e43 100644 --- a/arch/s390/kvm/gaccess.c +++ b/arch/s390/kvm/gaccess.c @@ -664,7 +664,7 @@ static unsigned long guest_translate(struct kvm_vcpu *vcpu, unsigned long gva, case ASCE_TYPE_REGION1: { union region1_table_entry rfte;

• if (kvm_is_error_gpa(vcpu->kvm, ptr))
  

• if (!kvm_is_gpa_in_memslot(vcpu->kvm, ptr))
  return PGM_ADDRESSING;
  

  if (deref_table(vcpu->kvm, ptr, &rfte.val)) return -EFAULT;

@@ -682,7 +682,7 @@ static unsigned long guest_translate(struct kvm_vcpu *vcpu, unsigned long gva, case ASCE_TYPE_REGION2: { union region2_table_entry rste;

• if (kvm_is_error_gpa(vcpu->kvm, ptr))
  

• if (!kvm_is_gpa_in_memslot(vcpu->kvm, ptr))
  return PGM_ADDRESSING;
  

  if (deref_table(vcpu->kvm, ptr, &rste.val)) return -EFAULT;

@@ -700,7 +700,7 @@ static unsigned long guest_translate(struct kvm_vcpu *vcpu, unsigned long gva, case ASCE_TYPE_REGION3: { union region3_table_entry rtte;

• if (kvm_is_error_gpa(vcpu->kvm, ptr))
  

• if (!kvm_is_gpa_in_memslot(vcpu->kvm, ptr))
  return PGM_ADDRESSING;
  

  if (deref_table(vcpu->kvm, ptr, &rtte.val)) return -EFAULT;

@@ -728,7 +728,7 @@ static unsigned long guest_translate(struct kvm_vcpu *vcpu, unsigned long gva, case ASCE_TYPE_SEGMENT: { union segment_table_entry ste;

• if (kvm_is_error_gpa(vcpu->kvm, ptr))
  

• if (!kvm_is_gpa_in_memslot(vcpu->kvm, ptr))
  return PGM_ADDRESSING;
  

  if (deref_table(vcpu->kvm, ptr, &ste.val)) return -EFAULT;

@@ -748,7 +748,7 @@ static unsigned long guest_translate(struct kvm_vcpu *vcpu, unsigned long gva, ptr = ste.fc0.pto * (PAGE_SIZE / 2) + vaddr.px * 8; } }

• if (kvm_is_error_gpa(vcpu->kvm, ptr))

• if (!kvm_is_gpa_in_memslot(vcpu->kvm, ptr)) return PGM_ADDRESSING; if (deref_table(vcpu->kvm, ptr, &pte.val)) return -EFAULT;

@@ -770,7 +770,7 @@ static unsigned long guest_translate(struct kvm_vcpu *vcpu, unsigned long gva, *prot = PROT_TYPE_IEP; return PGM_PROTECTION; }

• if (kvm_is_error_gpa(vcpu->kvm, raddr.addr))

• if (!kvm_is_gpa_in_memslot(vcpu->kvm, raddr.addr)) return PGM_ADDRESSING; *gpa = raddr.addr; return 0;

@@ -957,7 +957,7 @@ static int guest_range_to_gpas(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, return rc; } else { gpa = kvm_s390_real_to_abs(vcpu, ga);

• 	if (kvm_is_error_gpa(vcpu->kvm, gpa)) {
  

• 	if (!kvm_is_gpa_in_memslot(vcpu->kvm, gpa)) {
  	rc = PGM_ADDRESSING;
  	prot = PROT_NONE;
  }
  

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index ea63ac769889..3e5a1d7aa81a 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -2878,7 +2878,7 @@ static int kvm_s390_vm_mem_op_abs(struct kvm *kvm, struct kvm_s390_mem_op *mop) srcu_idx = srcu_read_lock(&kvm->srcu);

• if (kvm_is_error_gpa(kvm, mop->gaddr)) {

• if (!kvm_is_gpa_in_memslot(kvm, mop->gaddr)) { r = PGM_ADDRESSING; goto out_unlock; }

@@ -2940,7 +2940,7 @@ static int kvm_s390_vm_mem_op_cmpxchg(struct kvm *kvm, struct kvm_s390_mem_op *m srcu_idx = srcu_read_lock(&kvm->srcu);

• if (kvm_is_error_gpa(kvm, mop->gaddr)) {

• if (!kvm_is_gpa_in_memslot(kvm, mop->gaddr)) { r = PGM_ADDRESSING; goto out_unlock; }

diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c index f875a404a0a0..1be19cc9d73c 100644 --- a/arch/s390/kvm/priv.c +++ b/arch/s390/kvm/priv.c @@ -149,7 +149,7 @@ static int handle_set_prefix(struct kvm_vcpu *vcpu) * first page, since address is 8k aligned and memory pieces are always * at least 1MB aligned and have at least a size of 1MB. */

• if (kvm_is_error_gpa(vcpu->kvm, address))

• if (!kvm_is_gpa_in_memslot(vcpu->kvm, address)) return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);

kvm_s390_set_prefix(vcpu, address); @@ -464,7 +464,7 @@ static int handle_test_block(struct kvm_vcpu *vcpu) return kvm_s390_inject_prog_irq(vcpu, &vcpu->arch.pgm); addr = kvm_s390_real_to_abs(vcpu, addr);

• if (kvm_is_error_gpa(vcpu->kvm, addr))

• if (!kvm_is_gpa_in_memslot(vcpu->kvm, addr)) return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING); /*
  • We don't expect errors on modern systems, and do not care

diff --git a/arch/s390/kvm/sigp.c b/arch/s390/kvm/sigp.c index d9696b530064..55c34cb35428 100644 --- a/arch/s390/kvm/sigp.c +++ b/arch/s390/kvm/sigp.c @@ -172,7 +172,7 @@ static int __sigp_set_prefix(struct kvm_vcpu *vcpu, struct kvm_vcpu *dst_vcpu, * first page, since address is 8k aligned and memory pieces are always * at least 1MB aligned and have at least a size of 1MB. */

• if (kvm_is_error_gpa(vcpu->kvm, irq.u.prefix.address)) {

• if (!kvm_is_gpa_in_memslot(vcpu->kvm, irq.u.prefix.address)) { *reg &= 0xffffffff00000000UL; *reg |= SIGP_STATUS_INVALID_PARAMETER; return SIGP_CC_STATUS_STORED;

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 7e7fd25b09b3..d175b64488ec 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1788,11 +1788,11 @@ static inline hpa_t pfn_to_hpa(kvm_pfn_t pfn) return (hpa_t)pfn << PAGE_SHIFT; } -static inline bool kvm_is_error_gpa(struct kvm *kvm, gpa_t gpa) +static inline bool kvm_is_gpa_in_memslot(struct kvm *kvm, gpa_t gpa) { unsigned long hva = gfn_to_hva(kvm, gpa_to_gfn(gpa));

• return kvm_is_error_hva(hva);

• return !kvm_is_error_hva(hva); }

enum kvm_stat_kind {

base-commit: 687d8f4c3dea0758afd748968d91288220bbe7e3