KVM: s390: Fix and cleanup

- fix sigp sense/start/stop/inconsistency
 - cleanups
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Merge tag 'kvm-s390-next-5.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: Fix and cleanup

- fix sigp sense/start/stop/inconsistency
- cleanups
This commit is contained in:
Paolo Bonzini 2021-12-21 12:59:53 -05:00
commit 5e4e84f112
7 changed files with 155 additions and 88 deletions

View file

@ -3701,7 +3701,7 @@ KVM with the currently defined set of flags.
:Architectures: s390
:Type: vm ioctl
:Parameters: struct kvm_s390_skeys
:Returns: 0 on success, KVM_S390_GET_KEYS_NONE if guest is not using storage
:Returns: 0 on success, KVM_S390_GET_SKEYS_NONE if guest is not using storage
keys, negative value on error
This ioctl is used to get guest storage key values on the s390
@ -3720,7 +3720,7 @@ you want to get.
The count field is the number of consecutive frames (starting from start_gfn)
whose storage keys to get. The count field must be at least 1 and the maximum
allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range
allowed value is defined as KVM_S390_SKEYS_MAX. Values outside this range
will cause the ioctl to return -EINVAL.
The skeydata_addr field is the address to a buffer large enough to hold count
@ -3744,7 +3744,7 @@ you want to set.
The count field is the number of consecutive frames (starting from start_gfn)
whose storage keys to get. The count field must be at least 1 and the maximum
allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range
allowed value is defined as KVM_S390_SKEYS_MAX. Values outside this range
will cause the ioctl to return -EINVAL.
The skeydata_addr field is the address to a buffer containing count bytes of

View file

@ -91,23 +91,23 @@ struct uv_cb_header {
/* Query Ultravisor Information */
struct uv_cb_qui {
struct uv_cb_header header;
u64 reserved08;
u64 inst_calls_list[4];
u64 reserved30[2];
u64 uv_base_stor_len;
u64 reserved48;
u64 conf_base_phys_stor_len;
u64 conf_base_virt_stor_len;
u64 conf_virt_var_stor_len;
u64 cpu_stor_len;
u32 reserved70[3];
u32 max_num_sec_conf;
u64 max_guest_stor_addr;
u8 reserved88[158 - 136];
u16 max_guest_cpu_id;
u64 uv_feature_indications;
u8 reserveda0[200 - 168];
struct uv_cb_header header; /* 0x0000 */
u64 reserved08; /* 0x0008 */
u64 inst_calls_list[4]; /* 0x0010 */
u64 reserved30[2]; /* 0x0030 */
u64 uv_base_stor_len; /* 0x0040 */
u64 reserved48; /* 0x0048 */
u64 conf_base_phys_stor_len; /* 0x0050 */
u64 conf_base_virt_stor_len; /* 0x0058 */
u64 conf_virt_var_stor_len; /* 0x0060 */
u64 cpu_stor_len; /* 0x0068 */
u32 reserved70[3]; /* 0x0070 */
u32 max_num_sec_conf; /* 0x007c */
u64 max_guest_stor_addr; /* 0x0080 */
u8 reserved88[158 - 136]; /* 0x0088 */
u16 max_guest_cpu_id; /* 0x009e */
u64 uv_feature_indications; /* 0x00a0 */
u8 reserveda8[200 - 168]; /* 0x00a8 */
} __packed __aligned(8);
/* Initialize Ultravisor */

View file

@ -794,46 +794,100 @@ static int low_address_protection_enabled(struct kvm_vcpu *vcpu,
return 1;
}
static int guest_page_range(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
unsigned long *pages, unsigned long nr_pages,
const union asce asce, enum gacc_mode mode)
/**
* guest_range_to_gpas() - Calculate guest physical addresses of page fragments
* covering a logical range
* @vcpu: virtual cpu
* @ga: guest address, start of range
* @ar: access register
* @gpas: output argument, may be NULL
* @len: length of range in bytes
* @asce: address-space-control element to use for translation
* @mode: access mode
*
* Translate a logical range to a series of guest absolute addresses,
* such that the concatenation of page fragments starting at each gpa make up
* the whole range.
* The translation is performed as if done by the cpu for the given @asce, @ar,
* @mode and state of the @vcpu.
* If the translation causes an exception, its program interruption code is
* returned and the &struct kvm_s390_pgm_info pgm member of @vcpu is modified
* such that a subsequent call to kvm_s390_inject_prog_vcpu() will inject
* a correct exception into the guest.
* The resulting gpas are stored into @gpas, unless it is NULL.
*
* Note: All fragments except the first one start at the beginning of a page.
* When deriving the boundaries of a fragment from a gpa, all but the last
* fragment end at the end of the page.
*
* Return:
* * 0 - success
* * <0 - translation could not be performed, for example if guest
* memory could not be accessed
* * >0 - an access exception occurred. In this case the returned value
* is the program interruption code and the contents of pgm may
* be used to inject an exception into the guest.
*/
static int guest_range_to_gpas(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar,
unsigned long *gpas, unsigned long len,
const union asce asce, enum gacc_mode mode)
{
psw_t *psw = &vcpu->arch.sie_block->gpsw;
unsigned int offset = offset_in_page(ga);
unsigned int fragment_len;
int lap_enabled, rc = 0;
enum prot_type prot;
unsigned long gpa;
lap_enabled = low_address_protection_enabled(vcpu, asce);
while (nr_pages) {
while (min(PAGE_SIZE - offset, len) > 0) {
fragment_len = min(PAGE_SIZE - offset, len);
ga = kvm_s390_logical_to_effective(vcpu, ga);
if (mode == GACC_STORE && lap_enabled && is_low_address(ga))
return trans_exc(vcpu, PGM_PROTECTION, ga, ar, mode,
PROT_TYPE_LA);
ga &= PAGE_MASK;
if (psw_bits(*psw).dat) {
rc = guest_translate(vcpu, ga, pages, asce, mode, &prot);
rc = guest_translate(vcpu, ga, &gpa, asce, mode, &prot);
if (rc < 0)
return rc;
} else {
*pages = kvm_s390_real_to_abs(vcpu, ga);
if (kvm_is_error_gpa(vcpu->kvm, *pages))
gpa = kvm_s390_real_to_abs(vcpu, ga);
if (kvm_is_error_gpa(vcpu->kvm, gpa))
rc = PGM_ADDRESSING;
}
if (rc)
return trans_exc(vcpu, rc, ga, ar, mode, prot);
ga += PAGE_SIZE;
pages++;
nr_pages--;
if (gpas)
*gpas++ = gpa;
offset = 0;
ga += fragment_len;
len -= fragment_len;
}
return 0;
}
static int access_guest_page(struct kvm *kvm, enum gacc_mode mode, gpa_t gpa,
void *data, unsigned int len)
{
const unsigned int offset = offset_in_page(gpa);
const gfn_t gfn = gpa_to_gfn(gpa);
int rc;
if (mode == GACC_STORE)
rc = kvm_write_guest_page(kvm, gfn, data, offset, len);
else
rc = kvm_read_guest_page(kvm, gfn, data, offset, len);
return rc;
}
int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
unsigned long len, enum gacc_mode mode)
{
psw_t *psw = &vcpu->arch.sie_block->gpsw;
unsigned long _len, nr_pages, gpa, idx;
unsigned long pages_array[2];
unsigned long *pages;
unsigned long nr_pages, idx;
unsigned long gpa_array[2];
unsigned int fragment_len;
unsigned long *gpas;
int need_ipte_lock;
union asce asce;
int rc;
@ -845,49 +899,42 @@ int access_guest(struct kvm_vcpu *vcpu, unsigned long ga, u8 ar, void *data,
if (rc)
return rc;
nr_pages = (((ga & ~PAGE_MASK) + len - 1) >> PAGE_SHIFT) + 1;
pages = pages_array;
if (nr_pages > ARRAY_SIZE(pages_array))
pages = vmalloc(array_size(nr_pages, sizeof(unsigned long)));
if (!pages)
gpas = gpa_array;
if (nr_pages > ARRAY_SIZE(gpa_array))
gpas = vmalloc(array_size(nr_pages, sizeof(unsigned long)));
if (!gpas)
return -ENOMEM;
need_ipte_lock = psw_bits(*psw).dat && !asce.r;
if (need_ipte_lock)
ipte_lock(vcpu);
rc = guest_page_range(vcpu, ga, ar, pages, nr_pages, asce, mode);
rc = guest_range_to_gpas(vcpu, ga, ar, gpas, len, asce, mode);
for (idx = 0; idx < nr_pages && !rc; idx++) {
gpa = *(pages + idx) + (ga & ~PAGE_MASK);
_len = min(PAGE_SIZE - (gpa & ~PAGE_MASK), len);
if (mode == GACC_STORE)
rc = kvm_write_guest(vcpu->kvm, gpa, data, _len);
else
rc = kvm_read_guest(vcpu->kvm, gpa, data, _len);
len -= _len;
ga += _len;
data += _len;
fragment_len = min(PAGE_SIZE - offset_in_page(gpas[idx]), len);
rc = access_guest_page(vcpu->kvm, mode, gpas[idx], data, fragment_len);
len -= fragment_len;
data += fragment_len;
}
if (need_ipte_lock)
ipte_unlock(vcpu);
if (nr_pages > ARRAY_SIZE(pages_array))
vfree(pages);
if (nr_pages > ARRAY_SIZE(gpa_array))
vfree(gpas);
return rc;
}
int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
void *data, unsigned long len, enum gacc_mode mode)
{
unsigned long _len, gpa;
unsigned int fragment_len;
unsigned long gpa;
int rc = 0;
while (len && !rc) {
gpa = kvm_s390_real_to_abs(vcpu, gra);
_len = min(PAGE_SIZE - (gpa & ~PAGE_MASK), len);
if (mode)
rc = write_guest_abs(vcpu, gpa, data, _len);
else
rc = read_guest_abs(vcpu, gpa, data, _len);
len -= _len;
gra += _len;
data += _len;
fragment_len = min(PAGE_SIZE - offset_in_page(gpa), len);
rc = access_guest_page(vcpu->kvm, mode, gpa, data, fragment_len);
len -= fragment_len;
gra += fragment_len;
data += fragment_len;
}
return rc;
}
@ -909,8 +956,6 @@ int access_guest_real(struct kvm_vcpu *vcpu, unsigned long gra,
int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
unsigned long *gpa, enum gacc_mode mode)
{
psw_t *psw = &vcpu->arch.sie_block->gpsw;
enum prot_type prot;
union asce asce;
int rc;
@ -918,23 +963,7 @@ int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
rc = get_vcpu_asce(vcpu, &asce, gva, ar, mode);
if (rc)
return rc;
if (is_low_address(gva) && low_address_protection_enabled(vcpu, asce)) {
if (mode == GACC_STORE)
return trans_exc(vcpu, PGM_PROTECTION, gva, 0,
mode, PROT_TYPE_LA);
}
if (psw_bits(*psw).dat && !asce.r) { /* Use DAT? */
rc = guest_translate(vcpu, gva, gpa, asce, mode, &prot);
if (rc > 0)
return trans_exc(vcpu, rc, gva, 0, mode, prot);
} else {
*gpa = kvm_s390_real_to_abs(vcpu, gva);
if (kvm_is_error_gpa(vcpu->kvm, *gpa))
return trans_exc(vcpu, rc, gva, PGM_ADDRESSING, mode, 0);
}
return rc;
return guest_range_to_gpas(vcpu, gva, ar, gpa, 1, asce, mode);
}
/**
@ -948,17 +977,14 @@ int guest_translate_address(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
int check_gva_range(struct kvm_vcpu *vcpu, unsigned long gva, u8 ar,
unsigned long length, enum gacc_mode mode)
{
unsigned long gpa;
unsigned long currlen;
union asce asce;
int rc = 0;
rc = get_vcpu_asce(vcpu, &asce, gva, ar, mode);
if (rc)
return rc;
ipte_lock(vcpu);
while (length > 0 && !rc) {
currlen = min(length, PAGE_SIZE - (gva % PAGE_SIZE));
rc = guest_translate_address(vcpu, gva, ar, &gpa, mode);
gva += currlen;
length -= currlen;
}
rc = guest_range_to_gpas(vcpu, gva, ar, NULL, length, asce, mode);
ipte_unlock(vcpu);
return rc;

View file

@ -2116,6 +2116,13 @@ int kvm_s390_is_stop_irq_pending(struct kvm_vcpu *vcpu)
return test_bit(IRQ_PEND_SIGP_STOP, &li->pending_irqs);
}
int kvm_s390_is_restart_irq_pending(struct kvm_vcpu *vcpu)
{
struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
return test_bit(IRQ_PEND_RESTART, &li->pending_irqs);
}
void kvm_s390_clear_stop_irq(struct kvm_vcpu *vcpu)
{
struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;

View file

@ -4599,10 +4599,15 @@ int kvm_s390_vcpu_stop(struct kvm_vcpu *vcpu)
}
}
/* SIGP STOP and SIGP STOP AND STORE STATUS has been fully processed */
/*
* Set the VCPU to STOPPED and THEN clear the interrupt flag,
* now that the SIGP STOP and SIGP STOP AND STORE STATUS orders
* have been fully processed. This will ensure that the VCPU
* is kept BUSY if another VCPU is inquiring with SIGP SENSE.
*/
kvm_s390_set_cpuflags(vcpu, CPUSTAT_STOPPED);
kvm_s390_clear_stop_irq(vcpu);
kvm_s390_set_cpuflags(vcpu, CPUSTAT_STOPPED);
__disable_ibs_on_vcpu(vcpu);
for (i = 0; i < online_vcpus; i++) {

View file

@ -441,6 +441,7 @@ void kvm_s390_destroy_adapters(struct kvm *kvm);
int kvm_s390_ext_call_pending(struct kvm_vcpu *vcpu);
extern struct kvm_device_ops kvm_flic_ops;
int kvm_s390_is_stop_irq_pending(struct kvm_vcpu *vcpu);
int kvm_s390_is_restart_irq_pending(struct kvm_vcpu *vcpu);
void kvm_s390_clear_stop_irq(struct kvm_vcpu *vcpu);
int kvm_s390_set_irq_state(struct kvm_vcpu *vcpu,
void __user *buf, int len);

View file

@ -276,6 +276,34 @@ static int handle_sigp_dst(struct kvm_vcpu *vcpu, u8 order_code,
if (!dst_vcpu)
return SIGP_CC_NOT_OPERATIONAL;
/*
* SIGP RESTART, SIGP STOP, and SIGP STOP AND STORE STATUS orders
* are processed asynchronously. Until the affected VCPU finishes
* its work and calls back into KVM to clear the (RESTART or STOP)
* interrupt, we need to return any new non-reset orders "busy".
*
* This is important because a single VCPU could issue:
* 1) SIGP STOP $DESTINATION
* 2) SIGP SENSE $DESTINATION
*
* If the SIGP SENSE would not be rejected as "busy", it could
* return an incorrect answer as to whether the VCPU is STOPPED
* or OPERATING.
*/
if (order_code != SIGP_INITIAL_CPU_RESET &&
order_code != SIGP_CPU_RESET) {
/*
* Lockless check. Both SIGP STOP and SIGP (RE)START
* properly synchronize everything while processing
* their orders, while the guest cannot observe a
* difference when issuing other orders from two
* different VCPUs.
*/
if (kvm_s390_is_stop_irq_pending(dst_vcpu) ||
kvm_s390_is_restart_irq_pending(dst_vcpu))
return SIGP_CC_BUSY;
}
switch (order_code) {
case SIGP_SENSE:
vcpu->stat.instruction_sigp_sense++;