From 2bf3e74de4e5e33eb477e9ebe1839f9594173773 Mon Sep 17 00:00:00 2001 From: "Justin Terry (VM) via Qemu-devel" Date: Mon, 26 Feb 2018 09:13:34 -0800 Subject: [PATCH] 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) Message-Id: <1519665216-1078-7-git-send-email-juterry@microsoft.com> Signed-off-by: Paolo Bonzini Signed-off-by: Justin Terry (VM) via Qemu-devel --- target/i386/whpx-all.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/target/i386/whpx-all.c b/target/i386/whpx-all.c index 7e58d5f68c..47a6935288 100644 --- a/target/i386/whpx-all.c +++ b/target/i386/whpx-all.c @@ -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; -- GitLab