[PATCH] WHPX: Use QEMU values for trapped CPUID

[Sunil Muthuswamy]

Currently, WHPX is using some default values for the trapped CPUID
functions. These were not in sync with the QEMU values because the
CPUID values were never set with WHPX during VCPU initialization.
Additionally, at the moment, WHPX doesn't support setting CPUID
values in the hypervisor at runtime (i.e. after the partition has
been setup). That is needed to be able to set the CPUID values in
the hypervisor during VCPU init.
Until that support comes, use the QEMU values for the trapped CPUIDs.

Signed-off-by: Sunil Muthuswamy <address@hidden>
---
 target/i386/whpx-all.c | 42 ++++++++++++++++++------------------------
 1 file changed, 18 insertions(+), 24 deletions(-)

diff --git a/target/i386/whpx-all.c b/target/i386/whpx-all.c
index 35601b8176..4fe5a78b29 100644
--- a/target/i386/whpx-all.c
+++ b/target/i386/whpx-all.c
@@ -980,38 +980,32 @@ static int whpx_vcpu_run(CPUState *cpu)
             WHV_REGISTER_VALUE reg_values[5];
             WHV_REGISTER_NAME reg_names[5];
             UINT32 reg_count = 5;
-            UINT64 rip, rax, rcx, rdx, rbx;
+            UINT64 cpuid_fn, rip = 0, rax = 0, rcx = 0, rdx = 0, rbx = 0;
+            X86CPU *x86_cpu = X86_CPU(cpu);
+            CPUX86State *env = &x86_cpu->env;
 
             memset(reg_values, 0, sizeof(reg_values));
 
             rip = vcpu->exit_ctx.VpContext.Rip +
                   vcpu->exit_ctx.VpContext.InstructionLength;
-            switch (vcpu->exit_ctx.CpuidAccess.Rax) {
-            case 1:
-                rax = vcpu->exit_ctx.CpuidAccess.DefaultResultRax;
-                /* Advertise that we are running on a hypervisor */
-                rcx =
-                    vcpu->exit_ctx.CpuidAccess.DefaultResultRcx |
-                    CPUID_EXT_HYPERVISOR;
-
-                rdx = vcpu->exit_ctx.CpuidAccess.DefaultResultRdx;
-                rbx = vcpu->exit_ctx.CpuidAccess.DefaultResultRbx;
-                break;
+            cpuid_fn = vcpu->exit_ctx.CpuidAccess.Rax;
+
+            /*
+             * Ideally, these should be supplied to the hypervisor during VCPU
+             * initialization and it should be able to satisfy this request.
+             * But, currently, WHPX doesn't support setting CPUID values in the
+             * hypervisor once the partition has been setup, which is too late
+             * since VCPUs are realized later. For now, use the values from
+             * QEMU to satisfy these requests, until WHPX adds support for
+             * being able to set these values in the hypervisor at runtime.
+             */
+            cpu_x86_cpuid(env, cpuid_fn, 0, (UINT32 *)&rax, (UINT32 *)&rbx,
+                (UINT32 *)&rcx, (UINT32 *)&rdx);
+            switch (cpuid_fn) {
             case 0x80000001:
-                rax = vcpu->exit_ctx.CpuidAccess.DefaultResultRax;
                 /* Remove any support of OSVW */
-                rcx =
-                    vcpu->exit_ctx.CpuidAccess.DefaultResultRcx &
-                    ~CPUID_EXT3_OSVW;
-
-                rdx = vcpu->exit_ctx.CpuidAccess.DefaultResultRdx;
-                rbx = vcpu->exit_ctx.CpuidAccess.DefaultResultRbx;
+                rcx &= ~CPUID_EXT3_OSVW;
                 break;
-            default:
-                rax = vcpu->exit_ctx.CpuidAccess.DefaultResultRax;
-                rcx = vcpu->exit_ctx.CpuidAccess.DefaultResultRcx;
-                rdx = vcpu->exit_ctx.CpuidAccess.DefaultResultRdx;
-                rbx = vcpu->exit_ctx.CpuidAccess.DefaultResultRbx;
             }
 
             reg_names[0] = WHvX64RegisterRip;
-- 
2.17.1