From: David Hildenbrand <dahi@xxxxxxxxxxxxxxxxxx>
Without the storage-key facility, SIE won't interpret SSKE, ISKE and
RRBE for us. So let's add proper interception handlers that will be called
if lazy sske cannot be enabled.
Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Signed-off-by: David Hildenbrand <dahi@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
arch/s390/include/asm/page.h | 7 +-
arch/s390/include/asm/pgtable.h | 1 +
arch/s390/kvm/priv.c | 150 +++++++++++++++++++++++++++++++++++++---
arch/s390/mm/pgtable.c | 37 ++++++++++
4 files changed, 184 insertions(+), 11 deletions(-)
diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index 53eacbd..f874e7d5 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -109,13 +109,14 @@ static inline unsigned char page_get_storage_key(unsigned long addr)
static inline int page_reset_referenced(unsigned long addr)
{
- unsigned int ipm;
+ int cc;
asm volatile(
" rrbe 0,%1\n"
" ipm %0\n"
- : "=d" (ipm) : "a" (addr) : "cc");
- return !!(ipm & 0x20000000);
+ " srl %0,28\n"
+ : "=d" (cc) : "a" (addr) : "cc");
+ return cc;
}
/* Bits int the storage key */
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 2f6702e..9951e7e 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -896,6 +896,7 @@ int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
int cond_set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
unsigned char key, unsigned char *oldkey,
bool nq, bool mr, bool mc);
+int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr);
int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
unsigned char *key);
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 6745c2a..3db3be1 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -27,6 +27,7 @@
#include <asm/io.h>
#include <asm/ptrace.h>
#include <asm/compat.h>
+#include <asm/sclp.h>
#include "gaccess.h"
#include "kvm-s390.h"
#include "trace.h"
@@ -164,8 +165,7 @@ static int __skey_check_enable(struct kvm_vcpu *vcpu)
return rc;
}
-
-static int handle_skey(struct kvm_vcpu *vcpu)
+static int try_handle_skey(struct kvm_vcpu *vcpu)
{
int rc;
@@ -173,12 +173,146 @@ static int handle_skey(struct kvm_vcpu *vcpu)
rc = __skey_check_enable(vcpu);
if (rc)
return rc;
-
+ if (sclp.has_skey) {
+ /* with storage-key facility, SIE interprets it for us */
+ kvm_s390_retry_instr(vcpu);
+ VCPU_EVENT(vcpu, 4, "%s", "retrying storage key operation");
+ return -EAGAIN;
+ }
if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
+ return 0;
+}
- kvm_s390_retry_instr(vcpu);
- VCPU_EVENT(vcpu, 4, "%s", "retrying storage key operation");
+static int handle_iske(struct kvm_vcpu *vcpu)
+{
+ unsigned long addr;
+ unsigned char key;
+ int reg1, reg2;
+ int rc;
+
+ rc = try_handle_skey(vcpu);
+ if (rc)
+ return rc != -EAGAIN ? rc : 0;
+
+ kvm_s390_get_regs_rre(vcpu, ®1, ®2);
+
+ addr = vcpu->run->s.regs.gprs[reg2] & PAGE_MASK;
+ addr = kvm_s390_logical_to_effective(vcpu, addr);
+ addr = kvm_s390_real_to_abs(vcpu, addr);
+ addr = gfn_to_hva(vcpu->kvm, gpa_to_gfn(addr));
+ if (kvm_is_error_hva(addr))
+ return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
+
+ down_read(¤t->mm->mmap_sem);
+ rc = get_guest_storage_key(current->mm, addr, &key);
+ up_read(¤t->mm->mmap_sem);
+ if (rc)
+ return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
+ vcpu->run->s.regs.gprs[reg1] &= ~0xff;
+ vcpu->run->s.regs.gprs[reg1] |= key;
+ return 0;
+}
+
+static int handle_rrbe(struct kvm_vcpu *vcpu)
+{
+ unsigned long addr;
+ int reg1, reg2;
+ int rc;
+
+ rc = try_handle_skey(vcpu);
+ if (rc)
+ return rc != -EAGAIN ? rc : 0;
+
+ kvm_s390_get_regs_rre(vcpu, ®1, ®2);
+
+ addr = vcpu->run->s.regs.gprs[reg2] & PAGE_MASK;
+ addr = kvm_s390_logical_to_effective(vcpu, addr);
+ addr = kvm_s390_real_to_abs(vcpu, addr);
+ addr = gfn_to_hva(vcpu->kvm, gpa_to_gfn(addr));
+ if (kvm_is_error_hva(addr))
+ return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
+
+ down_read(¤t->mm->mmap_sem);
+ rc = reset_guest_reference_bit(current->mm, addr);
+ up_read(¤t->mm->mmap_sem);
+ if (rc < 0)
+ return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
+
+ kvm_s390_set_psw_cc(vcpu, rc);
+ return 0;
+}
+
+#define SSKE_NQ 0x8
+#define SSKE_MR 0x4
+#define SSKE_MC 0x2
+#define SSKE_MB 0x1
+static int handle_sske(struct kvm_vcpu *vcpu)
+{
+ unsigned char m3 = vcpu->arch.sie_block->ipb >> 28;
+ unsigned long start, end;
+ unsigned char key, oldkey;
+ int reg1, reg2;
+ int rc;
+
+ rc = try_handle_skey(vcpu);
+ if (rc)
+ return rc != -EAGAIN ? rc : 0;
+
+ if (!test_kvm_facility(vcpu->kvm, 8))
+ m3 &= ~SSKE_MB;
+ if (!test_kvm_facility(vcpu->kvm, 10))
+ m3 &= ~(SSKE_MC | SSKE_MR);
+ if (!test_kvm_facility(vcpu->kvm, 14))
+ m3 &= ~SSKE_NQ;
+
+ kvm_s390_get_regs_rre(vcpu, ®1, ®2);
+
+ key = vcpu->run->s.regs.gprs[reg1] & 0xfe;
+ start = vcpu->run->s.regs.gprs[reg2] & PAGE_MASK;
+ start = kvm_s390_logical_to_effective(vcpu, start);
+ if (m3 & SSKE_MB) {
+ /* start already designates an absolute address */
+ end = (start + (1UL << 20)) & ~((1UL << 20) - 1);
+ } else {
+ start = kvm_s390_real_to_abs(vcpu, start);
+ end = start + PAGE_SIZE;
+ }
+
+ while (start != end) {
+ unsigned long addr = gfn_to_hva(vcpu->kvm, gpa_to_gfn(start));
+
+ if (kvm_is_error_hva(addr))
+ return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
+
+ down_read(¤t->mm->mmap_sem);
+ rc = cond_set_guest_storage_key(current->mm, addr, key, &oldkey,
+ m3 & SSKE_NQ, m3 & SSKE_MR,
+ m3 & SSKE_MC);
+ up_read(¤t->mm->mmap_sem);
+ if (rc < 0)
+ return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
+ start += PAGE_SIZE;
+ };
+
+ if (m3 & (SSKE_MC | SSKE_MR)) {
+ if (m3 & SSKE_MB) {
+ /* skey in reg1 is unpredictable */
+ kvm_s390_set_psw_cc(vcpu, 3);
+ } else {
+ kvm_s390_set_psw_cc(vcpu, rc);
+ vcpu->run->s.regs.gprs[reg1] &= ~0xff00UL;
+ vcpu->run->s.regs.gprs[reg1] |= (u64) oldkey << 8;
+ }
+ }
+ if (m3 & SSKE_MB) {
+ if (psw_bits(vcpu->arch.sie_block->gpsw).eaba == PSW_AMODE_64BIT)
+ vcpu->run->s.regs.gprs[reg2] &= ~PAGE_MASK;
+ else
+ vcpu->run->s.regs.gprs[reg2] &= ~0xfffff000UL;
+ end = kvm_s390_logical_to_effective(vcpu, end);
+ vcpu->run->s.regs.gprs[reg2] |= end;
+ }
return 0;
}
@@ -586,9 +720,9 @@ static const intercept_handler_t b2_handlers[256] = {
[0x11] = handle_store_prefix,
[0x12] = handle_store_cpu_address,
[0x21] = handle_ipte_interlock,
- [0x29] = handle_skey,
- [0x2a] = handle_skey,
- [0x2b] = handle_skey,
+ [0x29] = handle_iske,
+ [0x2a] = handle_rrbe,
+ [0x2b] = handle_sske,
[0x2c] = handle_test_block,
[0x30] = handle_io_inst,
[0x31] = handle_io_inst,
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index e791e8b..fa286d0 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -572,6 +572,43 @@ int cond_set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
}
EXPORT_SYMBOL(cond_set_guest_storage_key);
+/**
+ * Reset a guest reference bit (rrbe), returning the reference and changed bit.
+ *
+ * Returns < 0 in case of error, otherwise the cc to be reported to the guest.
+ */
+int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr)
+{
+ spinlock_t *ptl;
+ pgste_t old, new;
+ pte_t *ptep;
+ int cc = 0;
+
+ ptep = get_locked_pte(mm, addr, &ptl);
+ if (unlikely(!ptep))
+ return -EFAULT;
+
+ new = old = pgste_get_lock(ptep);
+ /* Reset guest reference bit only */
+ pgste_val(new) &= ~PGSTE_GR_BIT;
+
+ if (!(pte_val(*ptep) & _PAGE_INVALID)) {
+ cc = page_reset_referenced(pte_val(*ptep) & PAGE_MASK);
+ /* Merge real referenced bit into host-set */
+ pgste_val(new) |= ((unsigned long) cc << 53) & PGSTE_HR_BIT;
+ }
+ /* Reflect guest's logical view, not physical */
+ cc |= (pgste_val(old) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 49;
+ /* Changing the guest storage key is considered a change of the page */
+ if ((pgste_val(new) ^ pgste_val(old)) & PGSTE_GR_BIT)
+ pgste_val(new) |= PGSTE_UC_BIT;
+
+ pgste_set_unlock(ptep, new);
+ pte_unmap_unlock(ptep, ptl);
+ return 0;
+}
+EXPORT_SYMBOL(reset_guest_reference_bit);
+
int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
unsigned char *key)
{
--
2.5.5
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