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s390x/kvm: Get rid of legacy_s390_alloc()

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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: Thomas Huth <thuth@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20210303130916.22553-2-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
This commit is contained in:
David Hildenbrand 2021-03-03 14:09:15 +01:00 committed by Cornelia Huck
parent 6157b0e197
commit 996e7e4b72
1 changed files with 5 additions and 38 deletions
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43
target/s390x/kvm.c
View file

@ -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;