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[Xen-devel] [PATCH v3 1/4] x86: stop handling MSR_IA32_BNDCFGS save/restore in implementation code

From: Paul Durrant <paul.durrant@xxxxxxxxxx>

Date: Thu, 14 Mar 2019 13:01:08 +0000

Cc: Kevin Tian <kevin.tian@xxxxxxxxx>, Wei Liu <wei.liu2@xxxxxxxxxx>, Jun Nakajima <jun.nakajima@xxxxxxxxx>, Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, Paul Durrant <paul.durrant@xxxxxxxxxx>, Jan Beulich <jbeulich@xxxxxxxx>, Roger Pau Monné <roger.pau@xxxxxxxxxx>

Delivery-date: Thu, 14 Mar 2019 13:02:07 +0000

List-id: Xen developer discussion <xen-devel.lists.xenproject.org>

Saving and restoring the value of this MSR is currently handled by implementation-specific code despite it being architectural. This patch moves handling of accesses to this MSR from hvm.c into the msr.c, thus allowing the common MSR save/restore code to handle it. NOTE: Because vmx_get/set_guest_bndcfgs() call vmx_vmcs_enter(), the struct vcpu pointer passed in, and hence the vcpu pointer passed to guest_rdmsr() cannot be const. Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx> --- Cc: Kevin Tian <kevin.tian@xxxxxxxxx> Cc: Jan Beulich <jbeulich@xxxxxxxx> Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> Cc: Wei Liu <wei.liu2@xxxxxxxxxx> Cc: "Roger Pau Monné" <roger.pau@xxxxxxxxxx> Cc: Jun Nakajima <jun.nakajima@xxxxxxxxx> v3: - Address further comments from Jan - Dropped Kevin's R-b because of change to vmx.c v2: - Addressed comments from Jan by largely removing hunks - Keeping Kevin's R-b since remaining hunks in vmx.c are as before --- xen/arch/x86/hvm/hvm.c | 14 ++------------ xen/arch/x86/hvm/vmx/vmx.c | 26 ++++++-------------------- xen/arch/x86/msr.c | 12 ++++++++++++ xen/include/asm-x86/hvm/hvm.h | 4 ++-- 4 files changed, 22 insertions(+), 34 deletions(-) diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index 8adbb61b57..e566d83f8b 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -1303,6 +1303,7 @@ static int hvm_load_cpu_xsave_states(struct domain *d, hvm_domain_context_t *h) static const uint32_t msrs_to_send[] = { MSR_SPEC_CTRL, MSR_INTEL_MISC_FEATURES_ENABLES, + MSR_IA32_BNDCFGS, MSR_AMD64_DR0_ADDRESS_MASK, MSR_AMD64_DR1_ADDRESS_MASK, MSR_AMD64_DR2_ADDRESS_MASK, @@ -1440,6 +1441,7 @@ static int hvm_load_cpu_msrs(struct domain *d, hvm_domain_context_t *h) case MSR_SPEC_CTRL: case MSR_INTEL_MISC_FEATURES_ENABLES: + case MSR_IA32_BNDCFGS: case MSR_AMD64_DR0_ADDRESS_MASK: case MSR_AMD64_DR1_ADDRESS_MASK ... MSR_AMD64_DR3_ADDRESS_MASK: rc = guest_wrmsr(v, ctxt->msr[i].index, ctxt->msr[i].val); @@ -3467,12 +3469,6 @@ int hvm_msr_read_intercept(unsigned int msr, uint64_t *msr_content) *msr_content = v->arch.hvm.msr_xss; break; - case MSR_IA32_BNDCFGS: - if ( !d->arch.cpuid->feat.mpx || - !hvm_get_guest_bndcfgs(v, msr_content) ) - goto gp_fault; - break; - case MSR_K8_ENABLE_C1E: case MSR_AMD64_NB_CFG: /* @@ -3619,12 +3615,6 @@ int hvm_msr_write_intercept(unsigned int msr, uint64_t msr_content, v->arch.hvm.msr_xss = msr_content; break; - case MSR_IA32_BNDCFGS: - if ( !d->arch.cpuid->feat.mpx || - !hvm_set_guest_bndcfgs(v, msr_content) ) - goto gp_fault; - break; - case MSR_AMD64_NB_CFG: /* ignore the write */ break; diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c index 725dd88c13..6445f44c3b 100644 --- a/xen/arch/x86/hvm/vmx/vmx.c +++ b/xen/arch/x86/hvm/vmx/vmx.c @@ -805,17 +805,6 @@ static unsigned int __init vmx_init_msr(void) static void vmx_save_msr(struct vcpu *v, struct hvm_msr *ctxt) { - vmx_vmcs_enter(v); - - if ( cpu_has_mpx && cpu_has_vmx_mpx ) - { - __vmread(GUEST_BNDCFGS, &ctxt->msr[ctxt->count].val); - if ( ctxt->msr[ctxt->count].val ) - ctxt->msr[ctxt->count++].index = MSR_IA32_BNDCFGS; - } - - vmx_vmcs_exit(v); - if ( cpu_has_xsaves && cpu_has_vmx_xsaves ) { ctxt->msr[ctxt->count].val = v->arch.hvm.msr_xss; @@ -835,14 +824,6 @@ static int vmx_load_msr(struct vcpu *v, struct hvm_msr *ctxt) { switch ( ctxt->msr[i].index ) { - case MSR_IA32_BNDCFGS: - if ( cpu_has_mpx && cpu_has_vmx_mpx && - is_canonical_address(ctxt->msr[i].val) && - !(ctxt->msr[i].val & IA32_BNDCFGS_RESERVED) ) - __vmwrite(GUEST_BNDCFGS, ctxt->msr[i].val); - else if ( ctxt->msr[i].val ) - err = -ENXIO; - break; case MSR_IA32_XSS: if ( cpu_has_xsaves && cpu_has_vmx_xsaves ) v->arch.hvm.msr_xss = ctxt->msr[i].val; @@ -1215,10 +1196,15 @@ static bool vmx_set_guest_bndcfgs(struct vcpu *v, u64 val) return true; } -static bool vmx_get_guest_bndcfgs(struct vcpu *v, u64 *val) +static bool vmx_get_guest_bndcfgs(const struct vcpu *cv, u64 *val) { + struct vcpu *v; + ASSERT(cpu_has_mpx && cpu_has_vmx_mpx); + /* Get a non-const pointer for vmx_vmcs_enter() */ + v = cv->domain->vcpu[cv->vcpu_id]; + vmx_vmcs_enter(v); __vmread(GUEST_BNDCFGS, val); vmx_vmcs_exit(v); diff --git a/xen/arch/x86/msr.c b/xen/arch/x86/msr.c index 4df4a59f4d..363fd63096 100644 --- a/xen/arch/x86/msr.c +++ b/xen/arch/x86/msr.c @@ -160,6 +160,12 @@ int guest_rdmsr(const struct vcpu *v, uint32_t msr, uint64_t *val) ret = guest_rdmsr_x2apic(v, msr, val); break; + case MSR_IA32_BNDCFGS: + if ( !cp->feat.mpx || !hvm_get_guest_bndcfgs(v, val) ) + goto gp_fault; + + break; + case 0x40000000 ... 0x400001ff: if ( is_viridian_domain(d) ) { @@ -323,6 +329,12 @@ int guest_wrmsr(struct vcpu *v, uint32_t msr, uint64_t val) ret = guest_wrmsr_x2apic(v, msr, val); break; + case MSR_IA32_BNDCFGS: + if ( !cp->feat.mpx || !hvm_set_guest_bndcfgs(v, val) ) + goto gp_fault; + + break; + case 0x40000000 ... 0x400001ff: if ( is_viridian_domain(d) ) { diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h index 53ffebb2c5..d41ed63232 100644 --- a/xen/include/asm-x86/hvm/hvm.h +++ b/xen/include/asm-x86/hvm/hvm.h @@ -149,7 +149,7 @@ struct hvm_function_table { int (*get_guest_pat)(struct vcpu *v, u64 *); int (*set_guest_pat)(struct vcpu *v, u64); - bool (*get_guest_bndcfgs)(struct vcpu *v, u64 *); + bool (*get_guest_bndcfgs)(const struct vcpu *v, u64 *); bool (*set_guest_bndcfgs)(struct vcpu *v, u64); void (*set_tsc_offset)(struct vcpu *v, u64 offset, u64 at_tsc); @@ -448,7 +448,7 @@ static inline unsigned long hvm_get_shadow_gs_base(struct vcpu *v) return hvm_funcs.get_shadow_gs_base(v); } -static inline bool hvm_get_guest_bndcfgs(struct vcpu *v, u64 *val) +static inline bool hvm_get_guest_bndcfgs(const struct vcpu *v, u64 *val) { return hvm_funcs.get_guest_bndcfgs && hvm_funcs.get_guest_bndcfgs(v, val); -- 2.20.1 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel

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