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authorSunil Muthuswamy <sunilmut@microsoft.com>2021-03-23 18:47:16 +0000
committerWei Liu <wei.liu@kernel.org>2021-03-24 11:35:24 +0000
commit6dc2a774cb4fdb524b7eb0b8db74198a1b4815ea (patch)
tree537cf3fba82d5d7e438f930a428b564c8d6b6e8e /arch/x86/kernel/cpu/mshyperv.c
parent1b60280834683dddf4975bbf9662a74f123ba770 (diff)
downloadlinux-6dc2a774cb4fdb524b7eb0b8db74198a1b4815ea.tar.bz2
x86/Hyper-V: Support for free page reporting
Linux has support for free page reporting now (36e66c554b5c) for virtualized environment. On Hyper-V when virtually backed VMs are configured, Hyper-V will advertise cold memory discard capability, when supported. This patch adds the support to hook into the free page reporting infrastructure and leverage the Hyper-V cold memory discard hint hypercall to report/free these pages back to the host. Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com> Tested-by: Matheus Castello <matheus@castello.eng.br> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/SN4PR2101MB0880121FA4E2FEC67F35C1DCC0649@SN4PR2101MB0880.namprd21.prod.outlook.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
Diffstat (limited to 'arch/x86/kernel/cpu/mshyperv.c')
-rw-r--r--arch/x86/kernel/cpu/mshyperv.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index cebed535ec56..3546d3e21787 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -265,12 +265,13 @@ static void __init ms_hyperv_init_platform(void)
* Extract the features and hints
*/
ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
- ms_hyperv.features_b = cpuid_ebx(HYPERV_CPUID_FEATURES);
+ ms_hyperv.priv_high = cpuid_ebx(HYPERV_CPUID_FEATURES);
ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES);
ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
- pr_info("Hyper-V: features 0x%x, hints 0x%x, misc 0x%x\n",
- ms_hyperv.features, ms_hyperv.hints, ms_hyperv.misc_features);
+ pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, hints 0x%x, misc 0x%x\n",
+ ms_hyperv.features, ms_hyperv.priv_high, ms_hyperv.hints,
+ ms_hyperv.misc_features);
ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS);
ms_hyperv.max_lp_index = cpuid_ebx(HYPERV_CPUID_IMPLEMENT_LIMITS);
@@ -316,7 +317,7 @@ static void __init ms_hyperv_init_platform(void)
x86_platform.calibrate_cpu = hv_get_tsc_khz;
}
- if (ms_hyperv.features_b & HV_ISOLATION) {
+ if (ms_hyperv.priv_high & HV_ISOLATION) {
ms_hyperv.isolation_config_a = cpuid_eax(HYPERV_CPUID_ISOLATION_CONFIG);
ms_hyperv.isolation_config_b = cpuid_ebx(HYPERV_CPUID_ISOLATION_CONFIG);