| Message ID | 20190221022445.3873-6-sean.j.christopherson@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | x86: nVMX: Address feedback on EPT series | expand |
On Wed, Feb 20, 2019 at 6:24 PM Sean Christopherson <sean.j.christopherson@intel.com> wrote: > > ...to document why there are two variations of "setup EPT" and when to > employ each variant. > > Suggested-by: Marc Orr <marcorr@google.com> > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> > --- > x86/vmx_tests.c | 29 ++++++++++++++++++++++++++++- > 1 file changed, 28 insertions(+), 1 deletion(-) > > diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c > index 9db2f2f..d800647 100644 > --- a/x86/vmx_tests.c > +++ b/x86/vmx_tests.c > @@ -1004,6 +1004,17 @@ static int insn_intercept_exit_handler(void) > return VMX_TEST_RESUME; > } > > +/** > + * __setup_ept - Setup the VMCS fields to enable Extended Page Tables (EPT) > + * @hpa: Host physical address of the top-level, a.k.a. root, EPT table > + * @enable_ad: Whether or not to enable Access/Dirty bits for EPT entries > + * > + * Returns 0 on success, 1 on failure. > + * > + * Note that @hpa doesn't need to point at actual memory if VM-Launch is > + * expected to fail, e.g. setup_dummy_ept() arbitrarily passes '0' to satisfy > + * the various EPTP consistency checks, but doesn't ensure backing for HPA '0'. > + */ > static int __setup_ept(u64 hpa, bool enable_ad) > { > if (!(ctrl_cpu_rev[0].clr & CPU_SECONDARY) || > @@ -1033,7 +1044,15 @@ static int __setup_ept(u64 hpa, bool enable_ad) > return 0; > } > > -/* Enables EPT and sets up the identity map. */ > +/** > + * setup_ept - Enable Extended Page Tables (EPT) and setup an identity map > + * @enable_ad: Whether or not to enable Access/Dirty bits for EPT entries > + * > + * Returns 0 on success, 1 on failure. > + * > + * This is the "real" function for setting up EPT tables, i.e. use this for > + * tests that need to run code in the guest with EPT enabled. > + */ > static int setup_ept(bool enable_ad) > { > unsigned long end_of_memory; > @@ -1057,6 +1076,14 @@ static int setup_ept(bool enable_ad) > return 0; > } > > +/** > + * setup_dummy_ept - Enable Extended Page Tables (EPT) with a dummy root HPA > + * > + * Setup EPT using a semi-arbitrary dummy root HPA. This function is intended > + * for use by tests that need EPT enabled to verify dependent VMCS controls > + * but never expect to fully enter the guest, i.e. don't need setup the actual > + * EPT tables. > + */ > static void setup_dummy_ept(void) > { > if (__setup_ept(0, false)) > -- > 2.20.1 > Reviewed-by: Marc Orr <marcorr@google.com>
diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c index 9db2f2f..d800647 100644 --- a/x86/vmx_tests.c +++ b/x86/vmx_tests.c @@ -1004,6 +1004,17 @@ static int insn_intercept_exit_handler(void) return VMX_TEST_RESUME; } +/** + * __setup_ept - Setup the VMCS fields to enable Extended Page Tables (EPT) + * @hpa: Host physical address of the top-level, a.k.a. root, EPT table + * @enable_ad: Whether or not to enable Access/Dirty bits for EPT entries + * + * Returns 0 on success, 1 on failure. + * + * Note that @hpa doesn't need to point at actual memory if VM-Launch is + * expected to fail, e.g. setup_dummy_ept() arbitrarily passes '0' to satisfy + * the various EPTP consistency checks, but doesn't ensure backing for HPA '0'. + */ static int __setup_ept(u64 hpa, bool enable_ad) { if (!(ctrl_cpu_rev[0].clr & CPU_SECONDARY) || @@ -1033,7 +1044,15 @@ static int __setup_ept(u64 hpa, bool enable_ad) return 0; } -/* Enables EPT and sets up the identity map. */ +/** + * setup_ept - Enable Extended Page Tables (EPT) and setup an identity map + * @enable_ad: Whether or not to enable Access/Dirty bits for EPT entries + * + * Returns 0 on success, 1 on failure. + * + * This is the "real" function for setting up EPT tables, i.e. use this for + * tests that need to run code in the guest with EPT enabled. + */ static int setup_ept(bool enable_ad) { unsigned long end_of_memory; @@ -1057,6 +1076,14 @@ static int setup_ept(bool enable_ad) return 0; } +/** + * setup_dummy_ept - Enable Extended Page Tables (EPT) with a dummy root HPA + * + * Setup EPT using a semi-arbitrary dummy root HPA. This function is intended + * for use by tests that need EPT enabled to verify dependent VMCS controls + * but never expect to fully enter the guest, i.e. don't need setup the actual + * EPT tables. + */ static void setup_dummy_ept(void) { if (__setup_ept(0, false))
...to document why there are two variations of "setup EPT" and when to employ each variant. Suggested-by: Marc Orr <marcorr@google.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> --- x86/vmx_tests.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-)