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authorWei Liu <wei.liu@kernel.org>2021-02-03 18:04:26 +0300
committerWei Liu <wei.liu@kernel.org>2021-02-11 11:47:06 +0300
commit80f73c9f7468b15484e3ee4a29870fc9fa0419cc (patch)
tree35e818f37bde5f9a0b00c2c08493cc5b0e7f2296 /arch/x86/hyperv
parent99a0f46af6a7715147e81c558d558021aad4e207 (diff)
downloadlinux-80f73c9f7468b15484e3ee4a29870fc9fa0419cc.tar.xz
x86/hyperv: handling hypercall page setup for root
When Linux is running as the root partition, the hypercall page will have already been setup by Hyper-V. Copy the content over to the allocated page. Add checks to hv_suspend & co to bail early because they are not supported in this setup yet. Signed-off-by: Lillian Grassin-Drake <ligrassi@microsoft.com> Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Co-Developed-by: Lillian Grassin-Drake <ligrassi@microsoft.com> Co-Developed-by: Sunil Muthuswamy <sunilmut@microsoft.com> Co-Developed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210203150435.27941-8-wei.liu@kernel.org
Diffstat (limited to 'arch/x86/hyperv')
-rw-r--r--arch/x86/hyperv/hv_init.c37
1 files changed, 34 insertions, 3 deletions
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 612c555fb9aa..aeea8fbf3c23 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -27,6 +27,7 @@
#include <linux/cpuhotplug.h>
#include <linux/syscore_ops.h>
#include <clocksource/hyperv_timer.h>
+#include <linux/highmem.h>
int hyperv_init_cpuhp;
u64 hv_current_partition_id = ~0ull;
@@ -286,6 +287,9 @@ static int hv_suspend(void)
union hv_x64_msr_hypercall_contents hypercall_msr;
int ret;
+ if (hv_root_partition)
+ return -EPERM;
+
/*
* Reset the hypercall page as it is going to be invalidated
* accross hibernation. Setting hv_hypercall_pg to NULL ensures
@@ -454,8 +458,35 @@ void __init hyperv_init(void)
rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
hypercall_msr.enable = 1;
- hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg);
- wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+
+ if (hv_root_partition) {
+ struct page *pg;
+ void *src, *dst;
+
+ /*
+ * For the root partition, the hypervisor will set up its
+ * hypercall page. The hypervisor guarantees it will not show
+ * up in the root's address space. The root can't change the
+ * location of the hypercall page.
+ *
+ * Order is important here. We must enable the hypercall page
+ * so it is populated with code, then copy the code to an
+ * executable page.
+ */
+ wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+
+ pg = vmalloc_to_page(hv_hypercall_pg);
+ dst = kmap(pg);
+ src = memremap(hypercall_msr.guest_physical_address << PAGE_SHIFT, PAGE_SIZE,
+ MEMREMAP_WB);
+ BUG_ON(!(src && dst));
+ memcpy(dst, src, HV_HYP_PAGE_SIZE);
+ memunmap(src);
+ kunmap(pg);
+ } else {
+ hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg);
+ wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+ }
/*
* hyperv_init() is called before LAPIC is initialized: see
@@ -604,7 +635,7 @@ EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized);
bool hv_is_hibernation_supported(void)
{
- return acpi_sleep_state_supported(ACPI_STATE_S4);
+ return !hv_root_partition && acpi_sleep_state_supported(ACPI_STATE_S4);
}
EXPORT_SYMBOL_GPL(hv_is_hibernation_supported);