On Tue, 8 Feb 2022 14:27:07 +0100 Pierre Morel <pmorel@xxxxxxxxxxxxx> wrote: > We need in several tests to check if the VM we are running in > is KVM. > Let's add the test. > > To check the VM type we use the STSI 3.2.2 instruction, let's > define it's response structure in a central header. > > Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxx> > --- > lib/s390x/stsi.h | 32 +++++++++++++++++++++++++++ > lib/s390x/vm.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++-- > lib/s390x/vm.h | 3 +++ > s390x/stsi.c | 23 ++------------------ > 4 files changed, 91 insertions(+), 23 deletions(-) > create mode 100644 lib/s390x/stsi.h > > diff --git a/lib/s390x/stsi.h b/lib/s390x/stsi.h > new file mode 100644 > index 00000000..9b40664f > --- /dev/null > +++ b/lib/s390x/stsi.h > @@ -0,0 +1,32 @@ > +/* SPDX-License-Identifier: GPL-2.0-or-later */ > +/* > + * Structures used to Store System Information > + * > + * Copyright IBM Corp. 2022 > + */ > + > +#ifndef _S390X_STSI_H_ > +#define _S390X_STSI_H_ > + > +struct sysinfo_3_2_2 { > + uint8_t reserved[31]; > + uint8_t count; > + struct { > + uint8_t reserved2[4]; > + uint16_t total_cpus; > + uint16_t conf_cpus; > + uint16_t standby_cpus; > + uint16_t reserved_cpus; > + uint8_t name[8]; > + uint32_t caf; > + uint8_t cpi[16]; > + uint8_t reserved5[3]; > + uint8_t ext_name_encoding; > + uint32_t reserved3; > + uint8_t uuid[16]; > + } vm[8]; > + uint8_t reserved4[1504]; > + uint8_t ext_names[8][256]; > +}; > + > +#endif /* _S390X_STSI_H_ */ > diff --git a/lib/s390x/vm.c b/lib/s390x/vm.c > index a5b92863..38886b76 100644 > --- a/lib/s390x/vm.c > +++ b/lib/s390x/vm.c > @@ -12,6 +12,7 @@ > #include <alloc_page.h> > #include <asm/arch_def.h> > #include "vm.h" > +#include "stsi.h" > > /** > * Detect whether we are running with TCG (instead of KVM) > @@ -26,9 +27,13 @@ bool vm_is_tcg(void) > if (initialized) > return is_tcg; > > - buf = alloc_page(); > - if (!buf) > + if (!vm_is_vm()) { > + initialized = true; > return false; > + } > + > + buf = alloc_page(); > + assert(buf); > > if (stsi(buf, 1, 1, 1)) > goto out; > @@ -43,3 +48,50 @@ out: > free_page(buf); > return is_tcg; > } > + > +/** > + * Detect whether we are running with KVM > + */ > + > +bool vm_is_kvm(void) I think this is too messy I think a cleaner approach would be to have one "detect_environment" function to call stsi and find out which environment we are running on. then the various vm_is_* would just be something like bool vm_is_kvm(void) { return detect_environment() == VM_IS_KVM; } obviously the detect_environment function would call stsi only once and then cache the result. bonus, we could make that function public too, so e.g. a testcase could do a switch, instead of having to do a series of nested ifs > +{ > + /* EBCDIC for "KVM/" */ > + const uint8_t kvm_ebcdic[] = { 0xd2, 0xe5, 0xd4, 0x61 }; > + static bool initialized; > + static bool is_kvm; > + struct sysinfo_3_2_2 *stsi_322; > + > + if (initialized) > + return is_kvm; > + > + if (!vm_is_vm() || vm_is_tcg()) { > + initialized = true; > + return is_kvm; > + } > + > + stsi_322 = alloc_page(); > + assert(stsi_322); > + > + if (stsi(stsi_322, 3, 2, 2)) > + goto out; > + > + /* > + * If the manufacturer string is "KVM/" in EBCDIC, then we > + * are on KVM. > + */ > + is_kvm = !memcmp(&stsi_322->vm[0].cpi, kvm_ebcdic, sizeof(kvm_ebcdic)); > + initialized = true; > +out: > + free_page(stsi_322); > + return is_kvm; > +} > + > +bool vm_is_lpar(void) > +{ > + return stsi_get_fc() == 2; > +} > + > +bool vm_is_vm(void) is it enough to call it vm? maybe zvm? I don't have a strong opinion, though > +{ > + return stsi_get_fc() == 3; > +} > diff --git a/lib/s390x/vm.h b/lib/s390x/vm.h > index 7abba0cc..3aaf76af 100644 > --- a/lib/s390x/vm.h > +++ b/lib/s390x/vm.h > @@ -9,5 +9,8 @@ > #define _S390X_VM_H_ > > bool vm_is_tcg(void); > +bool vm_is_kvm(void); > +bool vm_is_vm(void); > +bool vm_is_lpar(void); > > #endif /* _S390X_VM_H_ */ > diff --git a/s390x/stsi.c b/s390x/stsi.c > index 391f8849..1ed045e2 100644 > --- a/s390x/stsi.c > +++ b/s390x/stsi.c > @@ -13,27 +13,8 @@ > #include <asm/asm-offsets.h> > #include <asm/interrupt.h> > #include <smp.h> > +#include "stsi.h" > > -struct stsi_322 { > - uint8_t reserved[31]; > - uint8_t count; > - struct { > - uint8_t reserved2[4]; > - uint16_t total_cpus; > - uint16_t conf_cpus; > - uint16_t standby_cpus; > - uint16_t reserved_cpus; > - uint8_t name[8]; > - uint32_t caf; > - uint8_t cpi[16]; > - uint8_t reserved5[3]; > - uint8_t ext_name_encoding; > - uint32_t reserved3; > - uint8_t uuid[16]; > - } vm[8]; > - uint8_t reserved4[1504]; > - uint8_t ext_names[8][256]; > -}; > static uint8_t pagebuf[PAGE_SIZE * 2] __attribute__((aligned(PAGE_SIZE * 2))); > > static void test_specs(void) > @@ -91,7 +72,7 @@ static void test_3_2_2(void) > /* EBCDIC for "KVM/" */ > const uint8_t cpi_kvm[] = { 0xd2, 0xe5, 0xd4, 0x61 }; > const char vm_name_ext[] = "kvm-unit-test"; > - struct stsi_322 *data = (void *)pagebuf; > + struct sysinfo_3_2_2 *data = (void *)pagebuf; > > report_prefix_push("3.2.2"); >