KVM: SVM: Add manipulation functions for DRx intercepts

This patch wraps changes to the DRx intercepts of SVM into
seperate functions to abstract nested-svm better and prepare
the implementation of the vmcb-clean-bits feature.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

2 files changed, 61 insertions, 46 deletions

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 39f9ddf07136..11dbca7a582a 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -52,8 +52,7 @@ enum {
 
 struct __attribute__ ((__packed__)) vmcb_control_area {
         u32 intercept_cr;
-        u16 intercept_dr_read;
-        u16 intercept_dr_write;
+        u32 intercept_dr;
         u32 intercept_exceptions;
         u64 intercept;
         u8 reserved_1[42];
@@ -212,14 +211,22 @@ struct __attribute__ ((__packed__)) vmcb {
 #define INTERCEPT_CR4_WRITE     (16 + 4)
 #define INTERCEPT_CR8_WRITE     (16 + 8)
 
-#define INTERCEPT_DR0_MASK 1
-#define INTERCEPT_DR1_MASK (1 << 1)
-#define INTERCEPT_DR2_MASK (1 << 2)
-#define INTERCEPT_DR3_MASK (1 << 3)
-#define INTERCEPT_DR4_MASK (1 << 4)
-#define INTERCEPT_DR5_MASK (1 << 5)
-#define INTERCEPT_DR6_MASK (1 << 6)
-#define INTERCEPT_DR7_MASK (1 << 7)
+#define INTERCEPT_DR0_READ      0
+#define INTERCEPT_DR1_READ      1
+#define INTERCEPT_DR2_READ      2
+#define INTERCEPT_DR3_READ      3
+#define INTERCEPT_DR4_READ      4
+#define INTERCEPT_DR5_READ      5
+#define INTERCEPT_DR6_READ      6
+#define INTERCEPT_DR7_READ      7
+#define INTERCEPT_DR0_WRITE     (16 + 0)
+#define INTERCEPT_DR1_WRITE     (16 + 1)
+#define INTERCEPT_DR2_WRITE     (16 + 2)
+#define INTERCEPT_DR3_WRITE     (16 + 3)
+#define INTERCEPT_DR4_WRITE     (16 + 4)
+#define INTERCEPT_DR5_WRITE     (16 + 5)
+#define INTERCEPT_DR6_WRITE     (16 + 6)
+#define INTERCEPT_DR7_WRITE     (16 + 7)
 
 #define SVM_EVTINJ_VEC_MASK 0xff
 
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 1e7bb9c77084..a7c38eb9d2e3 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -99,8 +99,7 @@ struct nested_state {
 
         /* cache for intercepts of the guest */
         u32 intercept_cr;
-        u16 intercept_dr_read;
-        u16 intercept_dr_write;
+        u32 intercept_dr;
         u32 intercept_exceptions;
         u64 intercept;
 
@@ -204,8 +203,7 @@ static void recalc_intercepts(struct vcpu_svm *svm)
         g = &svm->nested;
 
         c->intercept_cr = h->intercept_cr | g->intercept_cr;
-        c->intercept_dr_read = h->intercept_dr_read | g->intercept_dr_read;
-        c->intercept_dr_write = h->intercept_dr_write | g->intercept_dr_write;
+        c->intercept_dr = h->intercept_dr | g->intercept_dr;
         c->intercept_exceptions = h->intercept_exceptions | g->intercept_exceptions;
         c->intercept = h->intercept | g->intercept;
 }
@@ -243,6 +241,24 @@ static inline bool is_cr_intercept(struct vcpu_svm *svm, int bit)
         return vmcb->control.intercept_cr & (1U << bit);
 }
 
+static inline void set_dr_intercept(struct vcpu_svm *svm, int bit)
+{
+        struct vmcb *vmcb = get_host_vmcb(svm);
+
+        vmcb->control.intercept_dr |= (1U << bit);
+
+        recalc_intercepts(svm);
+}
+
+static inline void clr_dr_intercept(struct vcpu_svm *svm, int bit)
+{
+        struct vmcb *vmcb = get_host_vmcb(svm);
+
+        vmcb->control.intercept_dr &= ~(1U << bit);
+
+        recalc_intercepts(svm);
+}
+
 static inline void enable_gif(struct vcpu_svm *svm)
 {
         svm->vcpu.arch.hflags |= HF_GIF_MASK;
@@ -807,23 +823,23 @@ static void init_vmcb(struct vcpu_svm *svm)
         set_cr_intercept(svm, INTERCEPT_CR4_WRITE);
         set_cr_intercept(svm, INTERCEPT_CR8_WRITE);
 
-        control->intercept_dr_read =    INTERCEPT_DR0_MASK |
-                                        INTERCEPT_DR1_MASK |
-                                        INTERCEPT_DR2_MASK |
-                                        INTERCEPT_DR3_MASK |
-                                        INTERCEPT_DR4_MASK |
-                                        INTERCEPT_DR5_MASK |
-                                        INTERCEPT_DR6_MASK |
-                                        INTERCEPT_DR7_MASK;
-
-        control->intercept_dr_write =   INTERCEPT_DR0_MASK |
-                                        INTERCEPT_DR1_MASK |
-                                        INTERCEPT_DR2_MASK |
-                                        INTERCEPT_DR3_MASK |
-                                        INTERCEPT_DR4_MASK |
-                                        INTERCEPT_DR5_MASK |
-                                        INTERCEPT_DR6_MASK |
-                                        INTERCEPT_DR7_MASK;
+        set_dr_intercept(svm, INTERCEPT_DR0_READ);
+        set_dr_intercept(svm, INTERCEPT_DR1_READ);
+        set_dr_intercept(svm, INTERCEPT_DR2_READ);
+        set_dr_intercept(svm, INTERCEPT_DR3_READ);
+        set_dr_intercept(svm, INTERCEPT_DR4_READ);
+        set_dr_intercept(svm, INTERCEPT_DR5_READ);
+        set_dr_intercept(svm, INTERCEPT_DR6_READ);
+        set_dr_intercept(svm, INTERCEPT_DR7_READ);
+
+        set_dr_intercept(svm, INTERCEPT_DR0_WRITE);
+        set_dr_intercept(svm, INTERCEPT_DR1_WRITE);
+        set_dr_intercept(svm, INTERCEPT_DR2_WRITE);
+        set_dr_intercept(svm, INTERCEPT_DR3_WRITE);
+        set_dr_intercept(svm, INTERCEPT_DR4_WRITE);
+        set_dr_intercept(svm, INTERCEPT_DR5_WRITE);
+        set_dr_intercept(svm, INTERCEPT_DR6_WRITE);
+        set_dr_intercept(svm, INTERCEPT_DR7_WRITE);
 
         control->intercept_exceptions = (1 << PF_VECTOR) |
                                         (1 << UD_VECTOR) |
@@ -1923,15 +1939,9 @@ static int nested_svm_intercept(struct vcpu_svm *svm)
                         vmexit = NESTED_EXIT_DONE;
                 break;
         }
-        case SVM_EXIT_READ_DR0 ... SVM_EXIT_READ_DR7: {
-                u32 dr_bits = 1 << (exit_code - SVM_EXIT_READ_DR0);
-                if (svm->nested.intercept_dr_read & dr_bits)
-                        vmexit = NESTED_EXIT_DONE;
-                break;
-        }
-        case SVM_EXIT_WRITE_DR0 ... SVM_EXIT_WRITE_DR7: {
-                u32 dr_bits = 1 << (exit_code - SVM_EXIT_WRITE_DR0);
-                if (svm->nested.intercept_dr_write & dr_bits)
+        case SVM_EXIT_READ_DR0 ... SVM_EXIT_WRITE_DR7: {
+                u32 bit = 1U << (exit_code - SVM_EXIT_READ_DR0);
+                if (svm->nested.intercept_dr & bit)
                         vmexit = NESTED_EXIT_DONE;
                 break;
         }
@@ -1977,8 +1987,7 @@ static inline void copy_vmcb_control_area(struct vmcb *dst_vmcb, struct vmcb *fr
         struct vmcb_control_area *from = &from_vmcb->control;
 
         dst->intercept_cr         = from->intercept_cr;
-        dst->intercept_dr_read    = from->intercept_dr_read;
-        dst->intercept_dr_write   = from->intercept_dr_write;
+        dst->intercept_dr         = from->intercept_dr;
         dst->intercept_exceptions = from->intercept_exceptions;
         dst->intercept            = from->intercept;
         dst->iopm_base_pa         = from->iopm_base_pa;
@@ -2280,8 +2289,7 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm)
 
         /* cache intercepts */
         svm->nested.intercept_cr         = nested_vmcb->control.intercept_cr;
-        svm->nested.intercept_dr_read    = nested_vmcb->control.intercept_dr_read;
-        svm->nested.intercept_dr_write   = nested_vmcb->control.intercept_dr_write;
+        svm->nested.intercept_dr         = nested_vmcb->control.intercept_dr;
         svm->nested.intercept_exceptions = nested_vmcb->control.intercept_exceptions;
         svm->nested.intercept            = nested_vmcb->control.intercept;
 
@@ -2906,8 +2914,8 @@ void dump_vmcb(struct kvm_vcpu *vcpu)
         pr_err("VMCB Control Area:\n");
         pr_err("cr_read:            %04x\n", control->intercept_cr & 0xffff);
         pr_err("cr_write:           %04x\n", control->intercept_cr >> 16);
-        pr_err("dr_read:            %04x\n", control->intercept_dr_read);
-        pr_err("dr_write:           %04x\n", control->intercept_dr_write);
+        pr_err("dr_read:            %04x\n", control->intercept_dr & 0xffff);
+        pr_err("dr_write:           %04x\n", control->intercept_dr >> 16);
         pr_err("exceptions:         %08x\n", control->intercept_exceptions);
         pr_err("intercepts:         %016llx\n", control->intercept);
         pr_err("pause filter count: %d\n", control->pause_filter_count);