[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen staging] libx86: Introduce x86_cpu_policies_are_compatible()
commit 588a966a572ec19253f8fb9495c8f926e07b1b87 Author: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> AuthorDate: Thu Jun 21 15:35:50 2018 +0100 Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> CommitDate: Thu Sep 26 13:40:18 2019 +0100 libx86: Introduce x86_cpu_policies_are_compatible() This helper will eventually be the core "can a guest configured like this run on the CPU?" logic. For now, it is just enough of a stub to allow us to replace the hypercall interface while retaining the previous behaviour. It will be expanded as various other bits of CPUID handling get cleaned up. Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx> Release-acked-by: Juergen Gross <jgross@xxxxxxxx> --- tools/tests/cpu-policy/Makefile | 2 +- tools/tests/cpu-policy/test-cpu-policy.c | 111 ++++++++++++++++++++++++++++++- xen/include/xen/lib/x86/cpu-policy.h | 26 ++++++++ xen/lib/x86/Makefile | 1 + xen/lib/x86/policy.c | 51 ++++++++++++++ 5 files changed, 188 insertions(+), 3 deletions(-) diff --git a/tools/tests/cpu-policy/Makefile b/tools/tests/cpu-policy/Makefile index fb548c9b9a..70ff154da6 100644 --- a/tools/tests/cpu-policy/Makefile +++ b/tools/tests/cpu-policy/Makefile @@ -39,7 +39,7 @@ CFLAGS += $(APPEND_CFLAGS) vpath %.c ../../../xen/lib/x86 -test-cpu-policy: test-cpu-policy.o msr.o cpuid.o +test-cpu-policy: test-cpu-policy.o msr.o cpuid.o policy.o $(CC) $(CFLAGS) $^ -o $@ -include $(DEPS_INCLUDE) diff --git a/tools/tests/cpu-policy/test-cpu-policy.c b/tools/tests/cpu-policy/test-cpu-policy.c index 201358d210..20ebed923b 100644 --- a/tools/tests/cpu-policy/test-cpu-policy.c +++ b/tools/tests/cpu-policy/test-cpu-policy.c @@ -9,8 +9,7 @@ #include <xen-tools/libs.h> #include <xen/asm/x86-vendors.h> -#include <xen/lib/x86/cpuid.h> -#include <xen/lib/x86/msr.h> +#include <xen/lib/x86/cpu-policy.h> #include <xen/domctl.h> static unsigned int nr_failures; @@ -503,6 +502,111 @@ static void test_cpuid_out_of_range_clearing(void) } } +static void test_is_compatible_success(void) +{ + static struct test { + const char *name; + struct cpuid_policy host_cpuid; + struct cpuid_policy guest_cpuid; + struct msr_policy host_msr; + struct msr_policy guest_msr; + } tests[] = { + { + .name = "Host CPUID faulting, Guest not", + .host_msr = { + .platform_info.cpuid_faulting = true, + }, + }, + { + .name = "Host CPUID faulting, Guest wanted", + .host_msr = { + .platform_info.cpuid_faulting = true, + }, + .guest_msr = { + .platform_info.cpuid_faulting = true, + }, + }, + }; + struct cpu_policy_errors no_errors = INIT_CPU_POLICY_ERRORS; + + printf("Testing policy compatibility success:\n"); + + for ( size_t i = 0; i < ARRAY_SIZE(tests); ++i ) + { + struct test *t = &tests[i]; + struct cpu_policy sys = { + &t->host_cpuid, + &t->host_msr, + }, new = { + &t->guest_cpuid, + &t->guest_msr, + }; + struct cpu_policy_errors e; + int res = x86_cpu_policies_are_compatible(&sys, &new, &e); + + /* Check the expected error output. */ + if ( res != 0 || memcmp(&no_errors, &e, sizeof(no_errors)) ) + fail(" Test '%s' expected no errors\n" + " got res %d { leaf %08x, subleaf %08x, msr %08x }\n", + t->name, res, e.leaf, e.subleaf, e.msr); + } +} + +static void test_is_compatible_failure(void) +{ + static struct test { + const char *name; + struct cpuid_policy host_cpuid; + struct cpuid_policy guest_cpuid; + struct msr_policy host_msr; + struct msr_policy guest_msr; + struct cpu_policy_errors e; + } tests[] = { + { + .name = "Host basic.max_leaf out of range", + .guest_cpuid.basic.max_leaf = 1, + .e = { 0, -1, -1 }, + }, + { + .name = "Host extd.max_leaf out of range", + .guest_cpuid.extd.max_leaf = 1, + .e = { 0x80000008, -1, -1 }, + }, + { + .name = "Host no CPUID faulting, Guest wanted", + .guest_msr = { + .platform_info.cpuid_faulting = true, + }, + .e = { -1, -1, 0xce }, + }, + }; + + printf("Testing policy compatibility failure:\n"); + + for ( size_t i = 0; i < ARRAY_SIZE(tests); ++i ) + { + struct test *t = &tests[i]; + struct cpu_policy sys = { + &t->host_cpuid, + &t->host_msr, + }, new = { + &t->guest_cpuid, + &t->guest_msr, + }; + struct cpu_policy_errors e; + int res = x86_cpu_policies_are_compatible(&sys, &new, &e); + + /* Check the expected error output. */ + if ( res == 0 || memcmp(&t->e, &e, sizeof(t->e)) ) + fail(" Test '%s' res %d\n" + " expected { leaf %08x, subleaf %08x, msr %08x }\n" + " got { leaf %08x, subleaf %08x, msr %08x }\n", + t->name, res, + t->e.leaf, t->e.subleaf, t->e.msr, + e.leaf, e.subleaf, e.msr); + } +} + int main(int argc, char **argv) { printf("CPU Policy unit tests\n"); @@ -516,6 +620,9 @@ int main(int argc, char **argv) test_msr_serialise_success(); test_msr_deserialise_failure(); + test_is_compatible_success(); + test_is_compatible_failure(); + if ( nr_failures ) printf("Done: %u failures\n", nr_failures); else diff --git a/xen/include/xen/lib/x86/cpu-policy.h b/xen/include/xen/lib/x86/cpu-policy.h index 6f07c4b493..5a2c4c7b2d 100644 --- a/xen/include/xen/lib/x86/cpu-policy.h +++ b/xen/include/xen/lib/x86/cpu-policy.h @@ -11,6 +11,32 @@ struct cpu_policy struct msr_policy *msr; }; +struct cpu_policy_errors +{ + uint32_t leaf, subleaf; + uint32_t msr; +}; + +#define INIT_CPU_POLICY_ERRORS { -1, -1, -1 } + +/* + * Calculate whether two policies are compatible. + * + * i.e. Can a VM configured with @guest run on a CPU supporting @host. + * + * @param host A cpu_policy describing the hardware capabilities. + * @param guest A cpu_policy describing the intended VM configuration. + * @param err Optional hint for error diagnostics. + * @returns -errno + * + * For typical usage, @host should be a system policy. In the case that an + * incompatibility is detected, the optional err pointer may identify the + * problematic leaf/subleaf and/or MSR. + */ +int x86_cpu_policies_are_compatible(const struct cpu_policy *host, + const struct cpu_policy *guest, + struct cpu_policy_errors *err); + #endif /* !XEN_LIB_X86_POLICIES_H */ /* diff --git a/xen/lib/x86/Makefile b/xen/lib/x86/Makefile index 2f9691e964..780ea05db1 100644 --- a/xen/lib/x86/Makefile +++ b/xen/lib/x86/Makefile @@ -1,2 +1,3 @@ obj-y += cpuid.o obj-y += msr.o +obj-y += policy.o diff --git a/xen/lib/x86/policy.c b/xen/lib/x86/policy.c new file mode 100644 index 0000000000..b156a304f4 --- /dev/null +++ b/xen/lib/x86/policy.c @@ -0,0 +1,51 @@ +#include "private.h" + +#include <xen/lib/x86/cpu-policy.h> + +int x86_cpu_policies_are_compatible(const struct cpu_policy *host, + const struct cpu_policy *guest, + struct cpu_policy_errors *err) +{ + struct cpu_policy_errors e = INIT_CPU_POLICY_ERRORS; + int ret = -EINVAL; + +#define NA XEN_CPUID_NO_SUBLEAF +#define FAIL_CPUID(l, s) \ + do { e.leaf = (l); e.subleaf = (s); goto out; } while ( 0 ) +#define FAIL_MSR(m) \ + do { e.msr = (m); goto out; } while ( 0 ) + + if ( guest->cpuid->basic.max_leaf > host->cpuid->basic.max_leaf ) + FAIL_CPUID(0, NA); + + if ( guest->cpuid->extd.max_leaf > host->cpuid->extd.max_leaf ) + FAIL_CPUID(0x80000008, NA); + + /* TODO: Audit more CPUID data. */ + + if ( ~host->msr->platform_info.raw & guest->msr->platform_info.raw ) + FAIL_MSR(MSR_INTEL_PLATFORM_INFO); + +#undef FAIL_MSR +#undef FAIL_CPUID +#undef NA + + /* Success. */ + ret = 0; + + out: + if ( err ) + *err = e; + + return ret; +} + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ -- generated by git-patchbot for /home/xen/git/xen.git#staging _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/xen-changelog
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