From 7d161f6537557520b52c2c7fb8321460f37ff933 Mon Sep 17 00:00:00 2001 From: Andrew Cooper Date: Mon, 17 Jun 2019 12:17:57 +0000 Subject: [PATCH] x86/svm: Fix svm_vmcb_dump() when used in current context VMExit doesn't switch all state. The FS/GS/TS/LDTR/GSBASE segment information, and SYSCALL/SYSENTER MSRs may still be cached in hardware, rather than up-to-date in the VMCB. Export svm_sync_vmcb() via svmdebug.h so svm_vmcb_dump() can use it, and bring the VMCB into sync in current context. As a minor optimisation, switch svm_sync_vmcb() to use svm_vm{load,save}_pa(), as svm->vmcb_pa is always correct, and this avoids a redundant __pa() translation behind the scenes. Signed-off-by: Andrew Cooper Reviewed-by: Jan Beulich Acked-by: Brian Woods --- xen/arch/x86/hvm/svm/svm.c | 6 +++--- xen/arch/x86/hvm/svm/svmdebug.c | 9 +++++++++ xen/include/asm-x86/hvm/svm/svmdebug.h | 1 + 3 files changed, 13 insertions(+), 3 deletions(-) diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c index cd6a6b382b..0eac9ce4c6 100644 --- a/xen/arch/x86/hvm/svm/svm.c +++ b/xen/arch/x86/hvm/svm/svm.c @@ -627,21 +627,21 @@ static void svm_cpuid_policy_changed(struct vcpu *v) cp->extd.ibpb ? MSR_INTERCEPT_NONE : MSR_INTERCEPT_RW); } -static void svm_sync_vmcb(struct vcpu *v, enum vmcb_sync_state new_state) +void svm_sync_vmcb(struct vcpu *v, enum vmcb_sync_state new_state) { struct svm_vcpu *svm = &v->arch.hvm.svm; if ( new_state == vmcb_needs_vmsave ) { if ( svm->vmcb_sync_state == vmcb_needs_vmload ) - svm_vmload(svm->vmcb); + svm_vmload_pa(svm->vmcb_pa); svm->vmcb_sync_state = new_state; } else { if ( svm->vmcb_sync_state == vmcb_needs_vmsave ) - svm_vmsave(svm->vmcb); + svm_vmsave_pa(svm->vmcb_pa); if ( svm->vmcb_sync_state != vmcb_needs_vmload ) svm->vmcb_sync_state = new_state; diff --git a/xen/arch/x86/hvm/svm/svmdebug.c b/xen/arch/x86/hvm/svm/svmdebug.c index d35e40596b..4293d8dba5 100644 --- a/xen/arch/x86/hvm/svm/svmdebug.c +++ b/xen/arch/x86/hvm/svm/svmdebug.c @@ -29,6 +29,15 @@ static void svm_dump_sel(const char *name, const struct segment_register *s) void svm_vmcb_dump(const char *from, const struct vmcb_struct *vmcb) { + struct vcpu *curr = current; + + /* + * If we are dumping the VMCB currently in context, some guest state may + * still be cached in hardware. Retrieve it. + */ + if ( vmcb == curr->arch.hvm.svm.vmcb ) + svm_sync_vmcb(curr, vmcb_in_sync); + printk("Dumping guest's current state at %s...\n", from); printk("Size of VMCB = %zu, paddr = %"PRIpaddr", vaddr = %p\n", sizeof(struct vmcb_struct), virt_to_maddr(vmcb), vmcb); diff --git a/xen/include/asm-x86/hvm/svm/svmdebug.h b/xen/include/asm-x86/hvm/svm/svmdebug.h index 658cdd3836..330c1d91aa 100644 --- a/xen/include/asm-x86/hvm/svm/svmdebug.h +++ b/xen/include/asm-x86/hvm/svm/svmdebug.h @@ -22,6 +22,7 @@ #include #include +void svm_sync_vmcb(struct vcpu *v, enum vmcb_sync_state new_state); void svm_vmcb_dump(const char *from, const struct vmcb_struct *vmcb); bool svm_vmcb_isvalid(const char *from, const struct vmcb_struct *vmcb, const struct vcpu *v, bool verbose); -- 2.30.2