| Message ID | 20210303130916.22553-2-david@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Get rid of legacy_s390_alloc() and phys_mem_set_alloc() | expand |
On 03/03/2021 14.09, David Hildenbrand wrote: > legacy_s390_alloc() was required for dealing with the absence of the ESOP > feature -- on old HW (< gen 10) and old z/VM versions (< 6.3). > > As z/VM v6.2 (and even v6.3) is no longer supported since 2017 [1] > and we don't expect to have real users on such old hardware, let's drop > legacy_s390_alloc(). > > Still check+report an error just in case someone still runs on > such old z/VM environments, or someone runs under weird nested KVM > setups (where we can manually disable ESOP via the CPU model). > > No need to check for KVM_CAP_GMAP - that should always be around on > kernels that also have KVM_CAP_DEVICE_CTRL (>= v3.15). Reviewed-by: Thomas Huth <thuth@redhat.com>
On 03.03.21 14:09, David Hildenbrand wrote: > legacy_s390_alloc() was required for dealing with the absence of the ESOP > feature -- on old HW (< gen 10) and old z/VM versions (< 6.3). > > As z/VM v6.2 (and even v6.3) is no longer supported since 2017 [1] > and we don't expect to have real users on such old hardware, let's drop > legacy_s390_alloc(). > > Still check+report an error just in case someone still runs on > such old z/VM environments, or someone runs under weird nested KVM > setups (where we can manually disable ESOP via the CPU model). > > No need to check for KVM_CAP_GMAP - that should always be around on > kernels that also have KVM_CAP_DEVICE_CTRL (>= v3.15). > > [1] https://www.ibm.com/support/lifecycle/search?q=z%2FVM > > Suggested-by: Cornelia Huck <cohuck@redhat.com> > Suggested-by: Thomas Huth <thuth@redhat.com> > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Richard Henderson <rth@twiddle.net> > Cc: Halil Pasic <pasic@linux.ibm.com> > Cc: Cornelia Huck <cohuck@redhat.com> > Cc: Christian Borntraeger <borntraeger@de.ibm.com> > Cc: Thomas Huth <thuth@redhat.com> > Cc: Igor Mammedov <imammedo@redhat.com> > Cc: Peter Xu <peterx@redhat.com> > Signed-off-by: David Hildenbrand <david@redhat.com> I agree, this should now be a corner case that we do not necessarily have to care about. > --- > target/s390x/kvm.c | 43 +++++-------------------------------------- > 1 file changed, 5 insertions(+), 38 deletions(-) > > diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c > index 7a892d663d..84b40572f2 100644 > --- a/target/s390x/kvm.c > +++ b/target/s390x/kvm.c > @@ -161,8 +161,6 @@ static int cap_protected; > > static int active_cmma; > > -static void *legacy_s390_alloc(size_t size, uint64_t *align, bool shared); > - > static int kvm_s390_query_mem_limit(uint64_t *memory_limit) > { > struct kvm_device_attr attr = { > @@ -349,6 +347,11 @@ int kvm_arch_init(MachineState *ms, KVMState *s) > "please use kernel 3.15 or newer"); > return -1; > } > + if (!kvm_check_extension(s, KVM_CAP_S390_COW)) { > + error_report("KVM is missing capability KVM_CAP_S390_COW - " > + "unsupported environment"); > + return -1; > + } > > cap_sync_regs = kvm_check_extension(s, KVM_CAP_SYNC_REGS); > cap_async_pf = kvm_check_extension(s, KVM_CAP_ASYNC_PF); > @@ -357,11 +360,6 @@ int kvm_arch_init(MachineState *ms, KVMState *s) > cap_vcpu_resets = kvm_check_extension(s, KVM_CAP_S390_VCPU_RESETS); > cap_protected = kvm_check_extension(s, KVM_CAP_S390_PROTECTED); > > - if (!kvm_check_extension(s, KVM_CAP_S390_GMAP) > - || !kvm_check_extension(s, KVM_CAP_S390_COW)) { > - phys_mem_set_alloc(legacy_s390_alloc); > - } > - > kvm_vm_enable_cap(s, KVM_CAP_S390_USER_SIGP, 0); > kvm_vm_enable_cap(s, KVM_CAP_S390_VECTOR_REGISTERS, 0); > kvm_vm_enable_cap(s, KVM_CAP_S390_USER_STSI, 0); > @@ -889,37 +887,6 @@ int kvm_s390_mem_op_pv(S390CPU *cpu, uint64_t offset, void *hostbuf, > return ret; > } > > -/* > - * Legacy layout for s390: > - * Older S390 KVM requires the topmost vma of the RAM to be > - * smaller than an system defined value, which is at least 256GB. > - * Larger systems have larger values. We put the guest between > - * the end of data segment (system break) and this value. We > - * use 32GB as a base to have enough room for the system break > - * to grow. We also have to use MAP parameters that avoid > - * read-only mapping of guest pages. > - */ > -static void *legacy_s390_alloc(size_t size, uint64_t *align, bool shared) > -{ > - static void *mem; > - > - if (mem) { > - /* we only support one allocation, which is enough for initial ram */ > - return NULL; > - } > - > - mem = mmap((void *) 0x800000000ULL, size, > - PROT_EXEC|PROT_READ|PROT_WRITE, > - MAP_SHARED | MAP_ANONYMOUS | MAP_FIXED, -1, 0); > - if (mem == MAP_FAILED) { > - mem = NULL; > - } > - if (mem && align) { > - *align = QEMU_VMALLOC_ALIGN; > - } > - return mem; > -} > - > static uint8_t const *sw_bp_inst; > static uint8_t sw_bp_ilen; > >
On Wed, 3 Mar 2021 14:09:15 +0100 David Hildenbrand <david@redhat.com> wrote: > legacy_s390_alloc() was required for dealing with the absence of the ESOP > feature -- on old HW (< gen 10) and old z/VM versions (< 6.3). > > As z/VM v6.2 (and even v6.3) is no longer supported since 2017 [1] > and we don't expect to have real users on such old hardware, let's drop > legacy_s390_alloc(). > > Still check+report an error just in case someone still runs on > such old z/VM environments, or someone runs under weird nested KVM > setups (where we can manually disable ESOP via the CPU model). > > No need to check for KVM_CAP_GMAP - that should always be around on > kernels that also have KVM_CAP_DEVICE_CTRL (>= v3.15). > > [1] https://www.ibm.com/support/lifecycle/search?q=z%2FVM > > Suggested-by: Cornelia Huck <cohuck@redhat.com> > Suggested-by: Thomas Huth <thuth@redhat.com> > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Richard Henderson <rth@twiddle.net> > Cc: Halil Pasic <pasic@linux.ibm.com> > Cc: Cornelia Huck <cohuck@redhat.com> > Cc: Christian Borntraeger <borntraeger@de.ibm.com> > Cc: Thomas Huth <thuth@redhat.com> > Cc: Igor Mammedov <imammedo@redhat.com> > Cc: Peter Xu <peterx@redhat.com> > Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Igor Mammedov <imammedo@redhat.com> > --- > target/s390x/kvm.c | 43 +++++-------------------------------------- > 1 file changed, 5 insertions(+), 38 deletions(-) > > diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c > index 7a892d663d..84b40572f2 100644 > --- a/target/s390x/kvm.c > +++ b/target/s390x/kvm.c > @@ -161,8 +161,6 @@ static int cap_protected; > > static int active_cmma; > > -static void *legacy_s390_alloc(size_t size, uint64_t *align, bool shared); > - > static int kvm_s390_query_mem_limit(uint64_t *memory_limit) > { > struct kvm_device_attr attr = { > @@ -349,6 +347,11 @@ int kvm_arch_init(MachineState *ms, KVMState *s) > "please use kernel 3.15 or newer"); > return -1; > } > + if (!kvm_check_extension(s, KVM_CAP_S390_COW)) { > + error_report("KVM is missing capability KVM_CAP_S390_COW - " > + "unsupported environment"); > + return -1; > + } > > cap_sync_regs = kvm_check_extension(s, KVM_CAP_SYNC_REGS); > cap_async_pf = kvm_check_extension(s, KVM_CAP_ASYNC_PF); > @@ -357,11 +360,6 @@ int kvm_arch_init(MachineState *ms, KVMState *s) > cap_vcpu_resets = kvm_check_extension(s, KVM_CAP_S390_VCPU_RESETS); > cap_protected = kvm_check_extension(s, KVM_CAP_S390_PROTECTED); > > - if (!kvm_check_extension(s, KVM_CAP_S390_GMAP) > - || !kvm_check_extension(s, KVM_CAP_S390_COW)) { > - phys_mem_set_alloc(legacy_s390_alloc); > - } > - > kvm_vm_enable_cap(s, KVM_CAP_S390_USER_SIGP, 0); > kvm_vm_enable_cap(s, KVM_CAP_S390_VECTOR_REGISTERS, 0); > kvm_vm_enable_cap(s, KVM_CAP_S390_USER_STSI, 0); > @@ -889,37 +887,6 @@ int kvm_s390_mem_op_pv(S390CPU *cpu, uint64_t offset, void *hostbuf, > return ret; > } > > -/* > - * Legacy layout for s390: > - * Older S390 KVM requires the topmost vma of the RAM to be > - * smaller than an system defined value, which is at least 256GB. > - * Larger systems have larger values. We put the guest between > - * the end of data segment (system break) and this value. We > - * use 32GB as a base to have enough room for the system break > - * to grow. We also have to use MAP parameters that avoid > - * read-only mapping of guest pages. > - */ > -static void *legacy_s390_alloc(size_t size, uint64_t *align, bool shared) > -{ > - static void *mem; > - > - if (mem) { > - /* we only support one allocation, which is enough for initial ram */ > - return NULL; > - } > - > - mem = mmap((void *) 0x800000000ULL, size, > - PROT_EXEC|PROT_READ|PROT_WRITE, > - MAP_SHARED | MAP_ANONYMOUS | MAP_FIXED, -1, 0); > - if (mem == MAP_FAILED) { > - mem = NULL; > - } > - if (mem && align) { > - *align = QEMU_VMALLOC_ALIGN; > - } > - return mem; > -} > - > static uint8_t const *sw_bp_inst; > static uint8_t sw_bp_ilen; >
diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c index 7a892d663d..84b40572f2 100644 --- a/target/s390x/kvm.c +++ b/target/s390x/kvm.c @@ -161,8 +161,6 @@ static int cap_protected; static int active_cmma; -static void *legacy_s390_alloc(size_t size, uint64_t *align, bool shared); - static int kvm_s390_query_mem_limit(uint64_t *memory_limit) { struct kvm_device_attr attr = { @@ -349,6 +347,11 @@ int kvm_arch_init(MachineState *ms, KVMState *s) "please use kernel 3.15 or newer"); return -1; } + if (!kvm_check_extension(s, KVM_CAP_S390_COW)) { + error_report("KVM is missing capability KVM_CAP_S390_COW - " + "unsupported environment"); + return -1; + } cap_sync_regs = kvm_check_extension(s, KVM_CAP_SYNC_REGS); cap_async_pf = kvm_check_extension(s, KVM_CAP_ASYNC_PF); @@ -357,11 +360,6 @@ int kvm_arch_init(MachineState *ms, KVMState *s) cap_vcpu_resets = kvm_check_extension(s, KVM_CAP_S390_VCPU_RESETS); cap_protected = kvm_check_extension(s, KVM_CAP_S390_PROTECTED); - if (!kvm_check_extension(s, KVM_CAP_S390_GMAP) - || !kvm_check_extension(s, KVM_CAP_S390_COW)) { - phys_mem_set_alloc(legacy_s390_alloc); - } - kvm_vm_enable_cap(s, KVM_CAP_S390_USER_SIGP, 0); kvm_vm_enable_cap(s, KVM_CAP_S390_VECTOR_REGISTERS, 0); kvm_vm_enable_cap(s, KVM_CAP_S390_USER_STSI, 0); @@ -889,37 +887,6 @@ int kvm_s390_mem_op_pv(S390CPU *cpu, uint64_t offset, void *hostbuf, return ret; } -/* - * Legacy layout for s390: - * Older S390 KVM requires the topmost vma of the RAM to be - * smaller than an system defined value, which is at least 256GB. - * Larger systems have larger values. We put the guest between - * the end of data segment (system break) and this value. We - * use 32GB as a base to have enough room for the system break - * to grow. We also have to use MAP parameters that avoid - * read-only mapping of guest pages. - */ -static void *legacy_s390_alloc(size_t size, uint64_t *align, bool shared) -{ - static void *mem; - - if (mem) { - /* we only support one allocation, which is enough for initial ram */ - return NULL; - } - - mem = mmap((void *) 0x800000000ULL, size, - PROT_EXEC|PROT_READ|PROT_WRITE, - MAP_SHARED | MAP_ANONYMOUS | MAP_FIXED, -1, 0); - if (mem == MAP_FAILED) { - mem = NULL; - } - if (mem && align) { - *align = QEMU_VMALLOC_ALIGN; - } - return mem; -} - static uint8_t const *sw_bp_inst; static uint8_t sw_bp_ilen;
legacy_s390_alloc() was required for dealing with the absence of the ESOP feature -- on old HW (< gen 10) and old z/VM versions (< 6.3). As z/VM v6.2 (and even v6.3) is no longer supported since 2017 [1] and we don't expect to have real users on such old hardware, let's drop legacy_s390_alloc(). Still check+report an error just in case someone still runs on such old z/VM environments, or someone runs under weird nested KVM setups (where we can manually disable ESOP via the CPU model). No need to check for KVM_CAP_GMAP - that should always be around on kernels that also have KVM_CAP_DEVICE_CTRL (>= v3.15). [1] https://www.ibm.com/support/lifecycle/search?q=z%2FVM Suggested-by: Cornelia Huck <cohuck@redhat.com> Suggested-by: Thomas Huth <thuth@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Halil Pasic <pasic@linux.ibm.com> Cc: Cornelia Huck <cohuck@redhat.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Thomas Huth <thuth@redhat.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> --- target/s390x/kvm.c | 43 +++++-------------------------------------- 1 file changed, 5 insertions(+), 38 deletions(-)