Fix WHPX issue leaking tpr values

Fixes an issue where if the tpr is assigned to the array but not a different
value from what is already expected on the vp the code will skip incrementing
the reg_count. In this case its possible that we set an invalid memory section
of the next call for DeliverabilityNotifications that was not expected.

The fix is to use a local variable to store the temporary tpr and only update
the array if the local tpr value is different than the vp context.

Signed-off-by: Justin Terry (VM) <juterry@microsoft.com>
Message-Id: <1519665216-1078-7-git-send-email-juterry@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Justin Terry (VM) via Qemu-devel <qemu-devel@nongnu.org>
This commit is contained in:
Justin Terry (VM) via Qemu-devel 2018-02-26 09:13:34 -08:00 committed by Paolo Bonzini
parent f875f04c2c
commit 2bf3e74de4

View File

@ -687,6 +687,7 @@ static void whpx_vcpu_pre_run(CPUState *cpu)
struct CPUX86State *env = (CPUArchState *)(cpu->env_ptr);
X86CPU *x86_cpu = X86_CPU(cpu);
int irq;
uint8_t tpr;
WHV_X64_PENDING_INTERRUPTION_REGISTER new_int = {0};
UINT32 reg_count = 0;
WHV_REGISTER_VALUE reg_values[3] = {0};
@ -746,9 +747,10 @@ static void whpx_vcpu_pre_run(CPUState *cpu)
}
/* Sync the TPR to the CR8 if was modified during the intercept */
reg_values[reg_count].Reg64 = cpu_get_apic_tpr(x86_cpu->apic_state);
if (reg_values[reg_count].Reg64 != vcpu->tpr) {
vcpu->tpr = reg_values[reg_count].Reg64;
tpr = cpu_get_apic_tpr(x86_cpu->apic_state);
if (tpr != vcpu->tpr) {
vcpu->tpr = tpr;
reg_values[reg_count].Reg64 = tpr;
cpu->exit_request = 1;
reg_names[reg_count] = WHvX64RegisterCr8;
reg_count += 1;